CVE-2020-26891

State: Published
Severity: Not scored
Published: Oct 19, 2020
Updated: Aug 4, 2024
Reserved: Oct 8, 2020

Description

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.

Scores

The record has no CVSS score.

Weaknesses

The record names no weakness.

Affected Products

Product	Versions
n/an/a	n/aAffected

References

https://github.com/matrix-org/synapse/pull/8444
https://matrix.org/blog/2020/10/15/synapse-1-21-2-released-and-security-advisory
https://github.com/matrix-org/synapse/releases/tag/v1.21.2
https://github.com/matrix-org/synapse/security/advisories/GHSA-3x8c-fmpc-5rmq

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