CVE-2024-53867: Matrix synapse Synapse Matrix Has A Partial Vulnerability

MODERATE
Advisory Identifier: GHSA-56w4-5538-8v8h
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CVSS 4.3
CWE-497
Published
Advisory Summary

CVE-2024-53867 is a MODERATE (CVSS 4.3) synapse matrix has a partial vulnerability (CWE-497: Exposure of Sensitive System Information to an Unauthorized Control Sphere) affecting Matrix synapse libraries in the PyPI ecosystem. The issue involves synapse matrix has a partial room state leak via sliding sync. Remediation is available by upgrading affected packages to version 1.120.1.

CVE-2024-53867 at a Glance

CVE Identifier CVE-2024-53867
GHSA Identifier GHSA-56w4-5538-8v8h
Severity MODERATE
CVSS v3.1 Base Score 4.3
CWE Classification CWE-497: Exposure of Sensitive System Information to an Unauthorized Control Sphere
Affected Product Matrix synapse
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 4.3

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality Low (C:L)
Integrity None (I:N)
Availability None (A:N)

How to Fix CVE-2024-53867

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-2024-53867, 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-497: Exposure of Sensitive System Information to an Unauthorized Control Sphere, where the product does not properly prevent sensitive system-level information from being accessed by unauthorized actors who do not have the same level of access to the underlying system as the product does. 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 The Sliding Sync feature on Synapse versions between 1.113.0rc1 and 1.120.0 can leak partial room state changes to users no longer in a room. Non-state events, like messages, are unaffected. ### Patches Synapse version 1.120.1 fixes the problem. ### Workarounds Disable Sliding Sync. ### References https://github.com/matrix-org/matrix-spec-proposals/pull/4186 https://github.com/element-hq/synapse/blob/d80cd57c54427687afcb48740d99219c88a0fff1/synapse/config/experimental.py#L341-L344 ### 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-2024-53867 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
≥ 1.113.0rc1
< 1.120.1
1.120.1

References

GitHub Advisory / Wiki ADVISORY
https://github.com/element-hq/synapse/security/advisories/GHSA-56w4-5538-8v8h
NVD — CVE-2024-53867 NVD
https://nvd.nist.gov/vuln/detail/CVE-2024-53867
Matrix synapse Source Repository REPOSITORY
https://github.com/matrix-org/matrix-spec-proposals/pull/4186
Matrix synapse Source Repository REPOSITORY
https://github.com/element-hq/synapse

Frequently Asked Questions

What is CVE-2024-53867?
CVE-2024-53867 is a security vulnerability in Matrix synapse involving Synapse Matrix has a partial room state leak via Sliding Sync under CWE-497: Exposure of Sensitive System Information to an Unauthorized Control Sphere.
Which Matrix synapse versions are affected?
Affected versions include releases prior to 1.120.1 across affected packages: matrix-synapse.
What version fixes CVE-2024-53867?
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 is the CVSS score of CVE-2024-53867?
CVE-2024-53867 has a CVSS v3.1 base score of 4.3 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N.
What CWE is associated with CVE-2024-53867?
CVE-2024-53867 is classified under CWE-497: Exposure of Sensitive System Information to an Unauthorized Control Sphere (The product does not properly prevent sensitive system-level information from being accessed by unauthorized actors who do not have the same level of access to the underlying system as the product does.).
How can I check PyPI dependencies for CVE-2024-53867?
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-56w4-5538-8v8h",
  "modified" : "2024-12-03T18:44:23Z",
  "published" : "2024-12-03T18:44:23Z",
  "aliases" : [ "CVE-2024-53867" ],
  "summary" : "Synapse Matrix has a partial room state leak via Sliding Sync",
  "details" : "### Impact\nThe Sliding Sync feature on Synapse versions between 1.113.0rc1 and 1.120.0 can leak partial room state changes to users no longer in a room. Non-state events, like messages, are unaffected.\n\n### Patches\nSynapse version 1.120.1 fixes the problem.\n\n### Workarounds\nDisable Sliding Sync.\n\n### References\nhttps://github.com/matrix-org/matrix-spec-proposals/pull/4186\nhttps://github.com/element-hq/synapse/blob/d80cd57c54427687afcb48740d99219c88a0fff1/synapse/config/experimental.py#L341-L344\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_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "matrix-synapse"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.113.0rc1"
      }, {
        "fixed" : "1.120.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/element-hq/synapse/security/advisories/GHSA-56w4-5538-8v8h"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2024-53867"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/matrix-org/matrix-spec-proposals/pull/4186"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/element-hq/synapse"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-497" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2024-12-03T18:44:23Z",
    "nvd_published_at" : "2024-12-03T17:15:12Z"
  }
}