Vulnerability Description
Matrix Synapse before 1.20.0 erroneously permits non-standard NaN, Infinity, and -Infinity JSON values in fields of m.room.member events, allowing remote attackers to execute a denial of service attack against the federation and common Matrix clients. If such a malformed event is accepted into the room's state, the impact is long-lasting and is not fixed by an upgrade to a newer version, requiring the event to be manually redacted instead. Since events are replicated to servers of other room members, the impact is not constrained to the server of the event sender.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Matrix | Synapse | < 1.20.0 |
| Fedoraproject | Fedora | 32 |
Related Weaknesses (CWE)
References
- https://github.com/matrix-org/synapse/security/advisories/GHSA-4mp3-385r-v63fPatchThird Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://github.com/matrix-org/synapse/security/advisories/GHSA-4mp3-385r-v63fPatchThird Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
FAQ
What is CVE-2020-26890?
CVE-2020-26890 is a vulnerability with a CVSS score of 7.5 (HIGH). Matrix Synapse before 1.20.0 erroneously permits non-standard NaN, Infinity, and -Infinity JSON values in fields of m.room.member events, allowing remote attackers to execute a denial of service attac...
How severe is CVE-2020-26890?
CVE-2020-26890 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2020-26890?
Check the references section above for vendor advisories and patch information. Affected products include: Matrix Synapse, Fedoraproject Fedora.