CVE-2020-26890: fedoraproject fedora Improper Input Validation

Vulnerability summary

CVE-2020-26890 is a high (CVSS 7.5) Improper Input Validation vulnerability in fedoraproject fedora. EPSS estimates a 3.00% chance of exploitation in the next 30 days, higher than 87.1% of scored vulnerabilities.

Timeline

1. 24-11-2020
   PublishedVulnerability first disclosed.
2. 04-08-2024
   Last modifiedVulnerability information updated.

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.

• CWE-20Improper Input ValidationThe product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.