Vulnerability-Lookup

CVE-2026-53541 (GCVE-0-2026-53541)

Vulnerability from cvelistv5 – Published: 2026-08-21 22:51 – Updated: 2026-08-24 20:03

Title

OliveTin has Unvalidated `ot_`-prefixed Arguments that Bypass Input Filtering

Summary

OliveTin gives access to predefined shell commands from a web interface. The `filterToDefinedArgumentsOnly` function in the executor is intended to discard any arguments not explicitly defined in the action's configuration. However, prior to commit ebffd9f040f791208aee1db2e5a8aecd1e3e603d, a special case allows any argument whose name starts with `ot_` to bypass this filter. While two system arguments (`ot_executionTrackingId` and `ot_username`) are injected by OliveTin and overridden, all other `ot_`-prefixed arguments supplied by the user pass through unmodified. These bypassed arguments are not type-checked — the validation loop only iterates over the action's defined arguments, so `ot_`-prefixed arguments skip all type safety checks entirely; set as environment variables — via `buildEnv()`, with completely unvalidated values, and passed to the executed command; and included in the template context — available as `.Arguments.ot_*` in template rendering. Commit ebffd9f040f791208aee1db2e5a8aecd1e3e603d contains a patch.

Severity

4.3 (Medium)


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

SSVC

Exploitation: poc Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-24 20:03 UTC

CWE

CWE-20 - Improper Input Validation

Assigner

GitHub_M mitre root

References

2 references

URL	Tags
https://github.com/OliveTin/OliveTin/security/adv…	x_refsource_CONFIRM
https://github.com/OliveTin/OliveTin/commit/ebffd…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version	CPE status
OliveTin	OliveTin	Affected: <= 2025.03.07	guessed

Show details on NVD website

JSON

To clipboard

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}

FKIE_CVE-2026-53541

Vulnerability from fkie_nvd - Published: 2026-08-21 23:16 - Updated: 2026-09-09 21:06

Severity

4.3 (Medium) - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

Summary

References

	URL	Tags
	security-advisories@github.com	https://github.com/OliveTin/OliveTin/commit/ebffd9f040f791208aee1db2e5a8aecd1e3e603d
	security-advisories@github.com	https://github.com/OliveTin/OliveTin/security/advisories/GHSA-prj9-97mp-mwh2
	134c704f-9b21-4f2e-91b3-4a467353bcc0	https://github.com/OliveTin/OliveTin/security/advisories/GHSA-prj9-97mp-mwh2

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "OliveTin",
          "vendor": "OliveTin",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c= 2025.03.07"
            }
          ]
        }
      ],
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    }
  ],
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    {
      "lang": "en",
      "value": "OliveTin gives access to predefined shell commands from a web interface. The `filterToDefinedArgumentsOnly` function in the executor is intended to discard any arguments not explicitly defined in the action\u0027s configuration. However, prior to commit ebffd9f040f791208aee1db2e5a8aecd1e3e603d, a special case allows any argument whose name starts with `ot_` to bypass this filter. While two system arguments (`ot_executionTrackingId` and `ot_username`) are injected by OliveTin and overridden, all other `ot_`-prefixed arguments supplied by the user pass through unmodified. These bypassed arguments are not type-checked \u2014 the validation loop only iterates over the action\u0027s defined arguments, so `ot_`-prefixed arguments skip all type safety checks entirely; set as environment variables \u2014 via `buildEnv()`, with completely unvalidated values, and passed to the executed command; and included in the template context \u2014 available as `.Arguments.ot_*` in template rendering. Commit ebffd9f040f791208aee1db2e5a8aecd1e3e603d contains a patch."
    }
  ],
  "id": "CVE-2026-53541",
  "lastModified": "2026-09-09T21:06:39.057",
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        "cvssData": {
          "attackComplexity": "LOW",
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          "confidentialityImpact": "NONE",
          "integrityImpact": "LOW",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N",
          "version": "3.1"
        },
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    }
  ]
}

GHSA-PRJ9-97MP-MWH2

Vulnerability from github – Published: 2026-06-24 17:43 – Updated: 2026-06-24 17:43

Summary

OliveTin has Unvalidated `ot_`-prefixed Arguments that Bypass Input Filtering

Details

Description

The filterToDefinedArgumentsOnly function in the executor is intended to discard any arguments not explicitly defined in the action's configuration. However, a special case allows any argument whose name starts with ot_ to bypass this filter. While two system arguments (ot_executionTrackingId and ot_username) are injected by OliveTin and overridden, all other ot_-prefixed arguments supplied by the user pass through unmodified.

These bypassed arguments are:

Not type-checked — the validation loop only iterates over the action's defined arguments, so ot_-prefixed arguments skip all type safety checks entirely.
Set as environment variables — via buildEnv(), with completely unvalidated values, and passed to the executed command.
Included in the template context — available as .Arguments.ot_* in template rendering.

Affected Code

Filter bypass — service/internal/executor/executor.go (lines 728–731):

func keepArgument(name string, definedNames map[string]struct{}) bool {
    _, ok := definedNames[name]
    return ok || strings.HasPrefix(name, "ot_")
}

System args only override two keys — service/internal/executor/executor.go (lines 742–745):

func injectSystemArgs(req *ExecutionRequest) {
    req.Arguments["ot_executionTrackingId"] = req.TrackingID
    req.Arguments["ot_username"] = req.AuthenticatedUser.Username
}

Any other ot_-prefixed argument (e.g., ot_malicious) survives both functions.

Unvalidated values become environment variables — service/internal/executor/executor.go (lines 867–882):

func buildEnv(args map[string]string) []string {
    ret := append(os.Environ(), "OLIVETIN=1")
    for k, v := range args {
        varName := fmt.Sprintf("%v", strings.TrimSpace(strings.ToUpper(k)))
        if varName == "" { continue }
        ret = append(ret, fmt.Sprintf("%v=%v", varName, v))
    }
    return ret
}

The value v is never validated. It can contain newlines, shell metacharacters, null bytes, or any arbitrary data.

Proof of Concept

An attacker sends a StartAction request with extra ot_-prefixed arguments:

{
  "bindingId": "<any-action-id>",
  "arguments": [
    { "name": "ot_custom_var", "value": "arbitrary unvalidated content \n with newlines" },
    { "name": "ot_another",    "value": "$(whoami)" }
  ]
}

These arguments:

Pass through filterToDefinedArgumentsOnly (the ot_ prefix exempts them).
Are never type-checked (not in the action's argument definitions).
Become environment variables OT_CUSTOM_VAR and OT_ANOTHER in the executed command's environment.
Are available in the template rendering context as .Arguments.ot_custom_var and .Arguments.ot_another.

Impact

Environment variable pollution — attacker can set arbitrary environment variables (with OT_ uppercased prefix) in the execution environment of any action they can trigger. Scripts or programs that read custom environment variables could be influenced.
Potential for secondary exploitation — if any executed script or command reads OT_-prefixed environment variables, the unvalidated content could cause unexpected behavior.
Template context pollution — although Go's text/template does not recursively evaluate data values (mitigating direct template injection), the extra arguments are accessible in the template context and could interact unexpectedly with custom template logic.

Suggested Fix

Remove the ot_ prefix exception from keepArgument, or restrict it to only the two known system arguments:

var systemArgs = map[string]struct{}{
    "ot_executionTrackingId": {},
    "ot_username":            {},
}

func keepArgument(name string, definedNames map[string]struct{}) bool {
    _, isDefined := definedNames[name]
    _, isSystem := systemArgs[name]
    return isDefined || isSystem
}

Discovery Methodology

Both vulnerabilities were identified through manual source code review of the OliveTin repository, focusing on:

Input validation boundaries (API request fields flowing into file system operations and execution contexts)
Argument filtering and type-checking logic in the executor
File path construction in the log persistence feature

No automated scanners or fuzzing tools were used. The review was conducted against the current main branch source code.

Severity

4.3 (Medium)


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

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{
  "affected": [
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/OliveTin/OliveTin"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.0.0-20260531214440-ebffd9f040f7"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-53541"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-20"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-06-24T17:43:50Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "### Description\n\nThe `filterToDefinedArgumentsOnly` function in the executor is intended to discard any arguments not explicitly defined in the action\u0027s configuration. However, a special case allows any argument whose name starts with `ot_` to bypass this filter. While two system arguments (`ot_executionTrackingId` and `ot_username`) are injected by OliveTin and overridden, all other `ot_`-prefixed arguments supplied by the user pass through unmodified.\n\nThese bypassed arguments are:\n\n1. **Not type-checked** \u2014 the validation loop only iterates over the action\u0027s defined arguments, so `ot_`-prefixed arguments skip all type safety checks entirely.\n2. **Set as environment variables** \u2014 via `buildEnv()`, with completely unvalidated values, and passed to the executed command.\n3. **Included in the template context** \u2014 available as `.Arguments.ot_*` in template rendering.\n\n### Affected Code\n\n**Filter bypass \u2014 `service/internal/executor/executor.go` (lines 728\u2013731):**\n\n```go\nfunc keepArgument(name string, definedNames map[string]struct{}) bool {\n    _, ok := definedNames[name]\n    return ok || strings.HasPrefix(name, \"ot_\")\n}\n```\n\n**System args only override two keys \u2014 `service/internal/executor/executor.go` (lines 742\u2013745):**\n\n```go\nfunc injectSystemArgs(req *ExecutionRequest) {\n    req.Arguments[\"ot_executionTrackingId\"] = req.TrackingID\n    req.Arguments[\"ot_username\"] = req.AuthenticatedUser.Username\n}\n```\n\nAny other `ot_`-prefixed argument (e.g., `ot_malicious`) survives both functions.\n\n**Unvalidated values become environment variables \u2014 `service/internal/executor/executor.go` (lines 867\u2013882):**\n\n```go\nfunc buildEnv(args map[string]string) []string {\n    ret := append(os.Environ(), \"OLIVETIN=1\")\n    for k, v := range args {\n        varName := fmt.Sprintf(\"%v\", strings.TrimSpace(strings.ToUpper(k)))\n        if varName == \"\" { continue }\n        ret = append(ret, fmt.Sprintf(\"%v=%v\", varName, v))\n    }\n    return ret\n}\n```\n\nThe value `v` is never validated. It can contain newlines, shell metacharacters, null bytes, or any arbitrary data.\n\n### Proof of Concept\n\nAn attacker sends a `StartAction` request with extra `ot_`-prefixed arguments:\n\n```json\n{\n  \"bindingId\": \"\u003cany-action-id\u003e\",\n  \"arguments\": [\n    { \"name\": \"ot_custom_var\", \"value\": \"arbitrary unvalidated content \\n with newlines\" },\n    { \"name\": \"ot_another\",    \"value\": \"$(whoami)\" }\n  ]\n}\n```\n\nThese arguments:\n\n- Pass through `filterToDefinedArgumentsOnly` (the `ot_` prefix exempts them).\n- Are never type-checked (not in the action\u0027s argument definitions).\n- Become environment variables `OT_CUSTOM_VAR` and `OT_ANOTHER` in the executed command\u0027s environment.\n- Are available in the template rendering context as `.Arguments.ot_custom_var` and `.Arguments.ot_another`.\n\n### Impact\n\n- **Environment variable pollution** \u2014 attacker can set arbitrary environment variables (with `OT_` uppercased prefix) in the execution environment of any action they can trigger. Scripts or programs that read custom environment variables could be influenced.\n- **Potential for secondary exploitation** \u2014 if any executed script or command reads `OT_`-prefixed environment variables, the unvalidated content could cause unexpected behavior.\n- **Template context pollution** \u2014 although Go\u0027s `text/template` does not recursively evaluate data values (mitigating direct template injection), the extra arguments are accessible in the template context and could interact unexpectedly with custom template logic.\n\n### Suggested Fix\n\nRemove the `ot_` prefix exception from `keepArgument`, or restrict it to only the two known system arguments:\n\n```go\nvar systemArgs = map[string]struct{}{\n    \"ot_executionTrackingId\": {},\n    \"ot_username\":            {},\n}\n\nfunc keepArgument(name string, definedNames map[string]struct{}) bool {\n    _, isDefined := definedNames[name]\n    _, isSystem := systemArgs[name]\n    return isDefined || isSystem\n}\n```\n\n---\n\n## Discovery Methodology\n\nBoth vulnerabilities were identified through manual source code review of the OliveTin repository, focusing on:\n\n- Input validation boundaries (API request fields flowing into file system operations and execution contexts)\n- Argument filtering and type-checking logic in the executor\n- File path construction in the log persistence feature\n\nNo automated scanners or fuzzing tools were used. The review was conducted against the current `main` branch source code.\n\n---",
  "id": "GHSA-prj9-97mp-mwh2",
  "modified": "2026-06-24T17:43:50Z",
  "published": "2026-06-24T17:43:50Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/OliveTin/OliveTin/security/advisories/GHSA-prj9-97mp-mwh2"
    },
    {
      "type": "WEB",
      "url": "https://github.com/OliveTin/OliveTin/commit/ebffd9f040f791208aee1db2e5a8aecd1e3e603d"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/OliveTin/OliveTin"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "OliveTin has Unvalidated `ot_`-prefixed Arguments that Bypass Input Filtering"
}

Sightings

Author	Source	Type	Date	Other

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.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted

CVE-2026-53541 (GCVE-0-2026-53541)

FKIE_CVE-2026-53541

GHSA-PRJ9-97MP-MWH2

Description

Affected Code

Proof of Concept

Impact

Suggested Fix

Discovery Methodology

Tags

Sightings

Nomenclature

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