QID 982971

QID 982971: Python (pip) Security Update for matrix-synapse (GHSA-3x8c-fmpc-5rmq)

Security update has been released for matrix-synapse to fix the vulnerability.

Note: The preceding description block is extracted directly from the security advisory. Using automation, we have attempted to clean and format it as much as possible without introducing additional issues.

The fallback authentication endpoint served via Synapse was vulnerable to cross-site scripting (XSS) attacks. The impact depends on the configuration of the domain that Synapse is deployed on, but may allow access to cookies and other browser data, CSRF vulnerabilities, and access to other resources served on the same domain or parent domains.

CVSS V3 rated as High - 6.1 severity.

CVSS V2 rated as Medium - 4.3 severity.

Solution

This is fixed by #8444, which is included in Synapse v1.21.0.Workaround:
If the homeserver is not configured to use reCAPTCHA, consent (terms of service), or single sign-on then the affected endpoint can be blocked at a reverse proxy:

* `/_matrix/client/r0/auth/.*/fallback/web`
* `/_matrix/client/unstable/auth/.*/fallback/web`

Vendor References

GHSA-3x8c-fmpc-5rmq - github.com/advisories/GHSA-3x8c-fmpc-5rmq

CVEs related to QID 982971

CVE-2020-26891 |

Software Advisories

Advisory ID	Software	Component	Link
GHSA-3x8c-fmpc-5rmq	matrix-synapse		github.com/advisories/GHSA-3x8c-fmpc-5rmq

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