CVE-2020-26257: Denial of service attack via incorrect parameters in Matrix Synapse
(updated )
A malicious or poorly-implemented homeserver can inject malformed events into a room by specifying a different room id in the path of a /send_join, /send_leave, /invite or /exchange_third_party_invite request.
This can lead to a denial of service in which future events will not be correctly sent to other servers over federation.
This affects any server which accepts federation requests from untrusted servers.
References
- github.com/advisories/GHSA-hxmp-pqch-c8mm
- github.com/matrix-org/synapse/blob/develop/CHANGES.md
- github.com/matrix-org/synapse/commit/3ce2f303f15f6ac3dc352298972dc6e04d9b7a8b
- github.com/matrix-org/synapse/pull/8776
- github.com/matrix-org/synapse/security/advisories/GHSA-hxmp-pqch-c8mm
- github.com/pypa/advisory-database/tree/main/vulns/matrix-synapse/PYSEC-2020-236.yaml
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/DBTIU3ZNBFWZ56V4X7JIAD33V5H2GOMC
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/QR4MMYZKX5N5GYGH4H5LBUUC5TLAFHI7
- nvd.nist.gov/vuln/detail/CVE-2020-26257
Code Behaviors & Features
Detect and mitigate CVE-2020-26257 with GitLab Dependency Scanning
Secure your software supply chain by verifying that all open source dependencies used in your projects contain no disclosed vulnerabilities. Dependency Scanning using SBOM also detects vulnerabilities from proprietary advisories that this site does not include. Learn more about Dependency Scanning using SBOM →