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Vulnerability · Published Jun 28, 2022 · Assigned by GitHub_M

CVE-2022-31052URL previews can crash Synapse media repositories or Synapse monoliths

Medium 6.5

In plain English

A medium-severity security flaw in synapse from matrix-org. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.7% (higher than 77% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)6.5Medium
Exploit odds (30 days)1.7%top 23.2% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

Synapse is an open source home server implementation for the Matrix chat network. In versions prior to 1.61.1 URL previews of some web pages can exhaust the available stack space for the Synapse process due to unbounded recursion. This is sometimes recoverable and leads to an error for the request causing the problem, but in other cases the Synapse process may crash altogether. It is possible to exploit this maliciously, either by malicious users on the homeserver, or by remote users sending URLs that a local user's client may automatically request a URL preview for. Remote users are not able to exploit this directly, because the URL preview endpoint is authenticated. Deployments with `url_preview_enabled: false` set in configuration are not affected. Deployments with `url_preview_enabled: true` set in configuration **are** affected. Deployments with no configuration value set for `url_preview_enabled` are not affected, because the default is `false`. Administrators of homeservers with URL previews enabled are advised to upgrade to v1.61.1 or higher. Users unable to upgrade should set `url_preview_enabled` to false.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Alpine:v3.20synapse1.61.1-r0ALPINE-CVE-2022-31052
Alpine:v3.21synapse1.61.1-r0ALPINE-CVE-2022-31052
Alpine:v3.22synapse1.61.1-r0ALPINE-CVE-2022-31052
Alpine:v3.23synapse1.61.1-r0ALPINE-CVE-2022-31052
Alpine:v3.24synapse1.61.1-r0ALPINE-CVE-2022-31052
Debian:14matrix-synapse1.61.1-1DEBIAN-CVE-2022-31052
PyPImatrix-synapse1.61.1GHSA-22p3-qrh9-cx32
PyPImatrix-synapse1.61.1PYSEC-2022-224

Affected products (as reported)

VendorProductVersions
matrix-org synapse < 1.61.1

Weakness: CWE-674 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

References