CVE-2024-52805: Matrix synapse Synapse Allows Unsupported Content Types Vulnerability

HIGH
Advisory Identifier: GHSA-rfq8-j7rh-8hf2
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CWE-770
Published
Advisory Summary

CVE-2024-52805 is a HIGH synapse allows unsupported content types vulnerability (CWE-770: Allocation of Resources Without Limits or Throttling) affecting Matrix synapse libraries in the PyPI ecosystem. The issue involves synapse allows unsupported content types to lead to memory exhaustion. Remediation is available by upgrading affected packages to version 1.120.1.

CVE-2024-52805 at a Glance

CVE Identifier CVE-2024-52805
GHSA Identifier GHSA-rfq8-j7rh-8hf2
Severity HIGH
CVSS v3.1 Base Score N/A
CWE Classification CWE-770: Allocation of Resources Without Limits or Throttling
Affected Product Matrix synapse
Package Ecosystem PyPI
Published Date
Last Updated

How to Fix CVE-2024-52805

To remediate this vulnerability, upgrade all affected Matrix synapse dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

matrix-synapse fixed: 1.120.1 
pip install matrix-synapse>=1.120.1
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show matrix-synapse

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2024-52805, inspect your installed packages using pip:

pip show matrix-synapse

Analyze the terminal output to locate any version of Matrix synapse in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.120.1), your application is affected.

Note: The pip show matrix-synapse command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-770: Allocation of Resources Without Limits or Throttling, where the product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated. In Matrix synapse, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Impact In Synapse before 1.120.1, `multipart/form-data` requests can in certain configurations transiently increase memory consumption beyond expected levels while processing the request, which can be used to amplify denial of service attacks. ### Patches Synapse 1.120.1 resolves the issue by denying requests with unsupported `multipart/form-data` content type. ### Workarounds Limiting request sizes or blocking the `multipart/form-data` content type before the requests reach Synapse, for example in a reverse proxy, alleviates the issue. Another approach that mitigates the attack is to use a low `max_upload_size` in Synapse. ### References - https://github.com/twisted/twisted/issues/4688#issuecomment-1167705518 - https://github.com/twisted/twisted/issues/4688#issuecomment-2385711609 ### For more information If you have any questions or comments about this advisory, please email us at [security at element.io](mailto:security@element.io).

CVE-2024-52805 Affected Matrix synapse Versions

1 component(s)
Fixed Versions:
1.120.1
Product / Package Ecosystem Affected Versions Fixed Version
matrix-synapse
pypi/matrix-synapse
PyPI
< 1.120.1
1.120.1

References

GitHub Advisory / Wiki ADVISORY
https://github.com/element-hq/synapse/security/advisories/GHSA-rfq8-j7rh-8hf2
NVD — CVE-2024-52805 NVD
https://nvd.nist.gov/vuln/detail/CVE-2024-52805
Matrix synapse Source Repository REPOSITORY
https://github.com/twisted/twisted/issues/4688#issuecomment-1167705518
Matrix synapse Source Repository REPOSITORY
https://github.com/twisted/twisted/issues/4688#issuecomment-2385711609
Matrix synapse Source Repository REPOSITORY
https://github.com/element-hq/synapse

Frequently Asked Questions

What is CVE-2024-52805?
CVE-2024-52805 is a security vulnerability in Matrix synapse involving Synapse allows unsupported content types to lead to memory exhaustion under CWE-770: Allocation of Resources Without Limits or Throttling.
Which Matrix synapse versions are affected?
Affected versions include releases prior to 1.120.1 across affected packages: matrix-synapse.
What version fixes CVE-2024-52805?
Upgrading to 1.120.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is matrix-synapse affected?
Yes, matrix-synapse is affected in releases prior to 1.120.1. Upgrade your dependency to 1.120.1 or later.
What CWE is associated with CVE-2024-52805?
CVE-2024-52805 is classified under CWE-770: Allocation of Resources Without Limits or Throttling (The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.).
How can I check PyPI dependencies for CVE-2024-52805?
Run the dependency tree command: 'pip show matrix-synapse'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-rfq8-j7rh-8hf2",
  "modified" : "2024-12-03T18:40:39Z",
  "published" : "2024-12-03T18:40:39Z",
  "aliases" : [ "CVE-2024-52805" ],
  "summary" : "Synapse allows unsupported content types to lead to memory exhaustion",
  "details" : "### Impact\n\nIn Synapse before 1.120.1, `multipart/form-data` requests can in certain configurations transiently increase memory consumption beyond expected levels while processing the request, which can be used to amplify denial of service attacks.\n\n### Patches\n\nSynapse 1.120.1 resolves the issue by denying requests with unsupported `multipart/form-data` content type.\n\n### Workarounds\n\nLimiting request sizes or blocking the `multipart/form-data` content type before the requests reach Synapse, for example in a reverse proxy, alleviates the issue. Another approach that mitigates the attack is to use a low `max_upload_size` in Synapse.\n\n### References\n\n- https://github.com/twisted/twisted/issues/4688#issuecomment-1167705518\n- https://github.com/twisted/twisted/issues/4688#issuecomment-2385711609\n\n### For more information\n\nIf you have any questions or comments about this advisory, please email us at [security at element.io](mailto:security@element.io).\n",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "matrix-synapse"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.120.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/element-hq/synapse/security/advisories/GHSA-rfq8-j7rh-8hf2"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2024-52805"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/twisted/twisted/issues/4688#issuecomment-1167705518"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/twisted/twisted/issues/4688#issuecomment-2385711609"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/element-hq/synapse"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-770" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2024-12-03T18:40:39Z",
    "nvd_published_at" : "2024-12-03T17:15:12Z"
  }
}