CVE-2021-21394 – matrix-synapse

Package

Manager: pip
Name: matrix-synapse
Vulnerable Version: >=0 <1.28.0

Severity

Level: Medium

CVSS v3.1: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS v4.0: CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

EPSS: 0.00519 pctl0.65823

Details

Denial of service (via resource exhaustion) due to improper input validation on third-party identifier endpoints ### Impact Missing input validation of some parameters on the endpoints used to confirm third-party identifiers could cause excessive use of disk space and memory leading to resource exhaustion. ### Patches The issue is fixed by #9321. ### Workarounds Depending on the needs and configuration of the homeserver a few options are available: 1. Using email as third-party identifiers be disabled by not configuring the `email` setting. 2. Using phone numbers as third-party identifiers can be disabled by ensuring that `account_threepid_delegates.msisdn` is not configured. 3. Additionally, the affected endpoint patterns can be blocked at a reverse proxy: * `^/_matrix/client/(r0|unstable)/register/email` * `^/_matrix/client/(r0|unstable)/register/msisdn` * `^/_matrix/client/(r0|unstable)/account/password` * `^/_matrix/client/(r0|unstable)/account/3pid`

Metadata

Created: 2021-04-13T15:12:51Z
Modified: 2024-09-24T20:08:23Z
Source: https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2021/04/GHSA-w9fg-xffh-p362/GHSA-w9fg-xffh-p362.json
CWE IDs: ["CWE-20"]
Alternative ID: GHSA-w9fg-xffh-p362
Finding: F184
Auto approve: 1