CVE-2023-42453: Matrix synapse Matrix-synapse Vulnerable To Improper Validation Vulnerability

MODERATE
Advisory Identifier: GHSA-7565-cq32-vx2x
Share
CVSS 3.1
CWE-285
Published
Advisory Summary

CVE-2023-42453 is a MODERATE (CVSS 3.1) matrix-synapse vulnerable to improper validation vulnerability (CWE-285: Improper Authorization) affecting Matrix synapse libraries in the PyPI ecosystem. The issue involves matrix-synapse vulnerable to improper validation of receipts allows forged read receipts. Remediation is available by upgrading affected packages to version 1.93.0.

CVE-2023-42453 at a Glance

CVE Identifier CVE-2023-42453
GHSA Identifier GHSA-7565-cq32-vx2x
Severity MODERATE
CVSS v3.1 Base Score 3.1
CWE Classification CWE-285: Improper Authorization
Affected Product Matrix synapse
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 3.1

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

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

How to Fix CVE-2023-42453

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: 1.93.0 
pip install matrix-synapse>=1.93.0
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-2023-42453, 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 1.93.0), 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-285: Improper Authorization, where the product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. 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 Users were able to forge read receipts for any event (if they knew the room ID and event ID). Note that the users were not able to view the events, but simply mark it as read. This could be confusing as clients will show the event as read by the user, even if they are not in the room. ### Patches https://github.com/matrix-org/synapse/pull/16327 ### Workarounds There is no workaround.

CVE-2023-42453 Affected Matrix synapse Versions

1 component(s)
Fixed Versions:
1.93.0
Product / Package Ecosystem Affected Versions Fixed Version
matrix-synapse
pypi/matrix-synapse
PyPI
≥ 0.34.0
< 1.93.0
1.93.0

References

GitHub Advisory / Wiki ADVISORY
https://github.com/matrix-org/synapse/security/advisories/GHSA-7565-cq32-vx2x
NVD — CVE-2023-42453 NVD
https://nvd.nist.gov/vuln/detail/CVE-2023-42453
Matrix synapse Source Repository REPOSITORY
https://github.com/matrix-org/synapse/pull/16327
Security Fix Commit FIX COMMIT
https://github.com/matrix-org/synapse/commit/63d28a88c1d18c64ea7e23b6dd7483e6d5dcf881
Matrix synapse Source Repository REPOSITORY
https://github.com/matrix-org/synapse
Matrix synapse Source Repository REPOSITORY
https://github.com/pypa/advisory-database/tree/main/vulns/matrix-synapse/PYSEC-2023-180.yaml
lists.fedoraproject.org/archives/list/packa... WEB
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/2AFB2Y3S2VCPCN5P2XCZTG24MBMZ7DM4
lists.fedoraproject.org/archives/list/packa... WEB
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/65QPC55I4D27HIZP7H2NQ34EOXHPP4AO
lists.fedoraproject.org/archives/list/packa... WEB
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/N6P4QULVUE254WI7XF2LWWOGHCYVFXFY
Matrix synapse Security Information SECURITY
https://security.gentoo.org/glsa/202401-12

Frequently Asked Questions

What is CVE-2023-42453?
CVE-2023-42453 is a security vulnerability in Matrix synapse involving matrix-synapse vulnerable to improper validation of receipts allows forged read receipts under CWE-285: Improper Authorization.
Which Matrix synapse versions are affected?
Affected versions include releases prior to 1.93.0 across affected packages: matrix-synapse.
What version fixes CVE-2023-42453?
Upgrading to 1.93.0 (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 1.93.0. Upgrade your dependency to 1.93.0 or later.
What is the CVSS score of CVE-2023-42453?
CVE-2023-42453 has a CVSS v3.1 base score of 3.1 (MODERATE) with vector string CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N.
What CWE is associated with CVE-2023-42453?
CVE-2023-42453 is classified under CWE-285: Improper Authorization (The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action.).
How can I check PyPI dependencies for CVE-2023-42453?
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-7565-cq32-vx2x",
  "modified" : "2024-09-24T17:49:17Z",
  "published" : "2023-09-26T19:20:38Z",
  "aliases" : [ "CVE-2023-42453" ],
  "summary" : "matrix-synapse vulnerable to improper validation of receipts allows forged read receipts",
  "details" : "### Impact\nUsers were able to forge read receipts for any event (if they knew the room ID and event ID). Note that the users were not able to view the events, but simply mark it as read. This could be confusing as clients will show the event as read by the user, even if they are not in the room.\n\n### Patches\nhttps://github.com/matrix-org/synapse/pull/16327\n\n### Workarounds\nThere is no workaround.\n",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "matrix-synapse"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0.34.0"
      }, {
        "fixed" : "1.93.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/matrix-org/synapse/security/advisories/GHSA-7565-cq32-vx2x"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2023-42453"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/matrix-org/synapse/pull/16327"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/matrix-org/synapse/commit/63d28a88c1d18c64ea7e23b6dd7483e6d5dcf881"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/matrix-org/synapse"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/advisory-database/tree/main/vulns/matrix-synapse/PYSEC-2023-180.yaml"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/2AFB2Y3S2VCPCN5P2XCZTG24MBMZ7DM4"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/65QPC55I4D27HIZP7H2NQ34EOXHPP4AO"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/N6P4QULVUE254WI7XF2LWWOGHCYVFXFY"
  }, {
    "type" : "WEB",
    "url" : "https://security.gentoo.org/glsa/202401-12"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-285" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2023-09-26T19:20:38Z",
    "nvd_published_at" : "2023-09-27T15:19:32Z"
  }
}