Open Redirect in Matrix Synapse
CVE-2021-21392
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 1.28.0 requests to user provided domains were not res…
Vulnerability class: Open Redirect
EPSS: 0.009 (55.5th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:H/A:N.
Affected products
- Matrix Synapse
- Matrix-org Synapse — versions < 1.28.0
- Fedoraproject Fedora — versions 34
Weakness classification (CWE)
References
- security-advisories@github.com (Product, Third Party Advisory, x_refsource_MISC)
- security-advisories@github.com (x_refsource_CONFIRM, Patch, Third Party Advisory)
- 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-2021-21392?
- CVE-2021-21392 is a medium-severity vulnerability in Matrix Synapse, classified under URL Redirection to Untrusted Site (Open Redirect). CVSS score: 6.3/10. Published 2021-04-12.
- How severe is CVE-2021-21392?
- Medium severity. CVSS v3 base score is 6.3 out of 10.