Resource exhaustion in Matrix Synapse
CVE-2021-21274
Synapse is a Matrix reference homeserver written in python (pypi package matrix-synapse). Matrix is an ecosystem for open federated Instant Messaging and VoIP. In Synapse before version 1.25.0, a malicious homeserver could redirect request…
Vulnerability class: DoS (Denial of Service)
EPSS: 0.022 (80.2th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L.
Affected products
- Matrix Synapse
- Matrix-org Synapse — versions >=0.99.0, < 1.25.0
- Fedoraproject Fedora — versions 34
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Patch, Third Party Advisory)
- security-advisories@github.com (Third Party Advisory, x_refsource_MISC)
- security-advisories@github.com (Patch, Third Party Advisory, x_refsource_MISC)
- security-advisories@github.com (Patch, Third Party Advisory, x_refsource_MISC)
- security-advisories@github.com (x_refsource_FEDORA, vendor-advisory)
Frequently asked questions
- What is CVE-2021-21274?
- CVE-2021-21274 is a medium-severity vulnerability in Matrix Synapse, classified under Uncontrolled Resource Consumption. CVSS score: 4.3/10. Published 2021-02-26.
- How severe is CVE-2021-21274?
- Medium severity. CVSS v3 base score is 4.3 out of 10.