VDB
CVE-2020-26891
CVE-2020-26891
PUBLISHED
CVSS 6.099999904632568 MEDIUM
AuthRestServlet in Matrix Synapse before 1.21.0 is vulnerable to XSS due to unsafe interpolation of the session GET parameter. This allows a remote attacker to execute an XSS attack on the domain Synapse is hosted on, by supplying the victim user with a malicious URL to the /_matrix/client/r0/auth/*/fallback/web or /_matrix/client/unstable/auth/*/fallback/web Synapse endpoints.
EPSS 1.92% · 79.6th percentile
Risk Scores
CVSS 3.1
6.099999904632568
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
EPSS Score
1.92%
79.6th percentile
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Ubuntu:Pro:18.04:LTS | matrix-synapse | 0, 0.19.2+dfsg-6, 0.24.0+dfsg-1 |
| Ubuntu:Pro:20.04:LTS | matrix-synapse | 1.8.0-1, 1.7.3-1, 1.9.0-1 |
| Ubuntu:Pro:22.04:LTS | matrix-synapse | 1.39.0-1, 1.47.0-2, 1.47.1-1 |
Timeline
- Oct 16, 2020 CVE Published
- Apr 14, 2021 EPSS Score
- Jun 23, 2021 EPSS Score
- Aug 25, 2021 EPSS Score
- Dec 29, 2021 EPSS Score
- Jan 6, 2022 EPSS Score
- Feb 4, 2022 EPSS Score
- Mar 2, 2022 EPSS Score
- May 4, 2022 EPSS Score
- Jul 6, 2022 EPSS Score
- Sep 9, 2022 EPSS Score
- Nov 11, 2022 EPSS Score
References
- https://ubuntu.com/security/CVE-2020-26891 advisory
- https://github.com/matrix-org/synapse/pull/8444 fix
- https://github.com/matrix-org/synapse/releases third-party-advisory
- https://matrix.org/blog/2020/10/15/synapse-1-21-2-released-and-security-advisory third-party-advisory
- https://www.cve.org/CVERecord?id=CVE-2020-26891 third-party-advisory