CVE-2021-29471
11.05.2021, 15:15
Synapse is a Matrix reference homeserver written in python (pypi package matrix-synapse). Matrix is an ecosystem for open federated Instant Messaging and VoIP. In Synapse before version 1.33.2 "Push rules" can specify conditions under which they will match, including `event_match`, which matches event content against a pattern including wildcards. Certain patterns can cause very poor performance in the matching engine, leading to a denial-of-service when processing moderate length events. The issue is patched in version 1.33.2. A potential workaround might be to prevent users from making custom push rules, by blocking such requests at a reverse-proxy.Enginsight
| Vendor | Product | Version |
|---|---|---|
| matrix | synapse | 𝑥 < 1.33.2 |
𝑥
= Vulnerable software versions
Ubuntu Releases
Common Weakness Enumeration
- CWE-400 - Uncontrolled Resource ConsumptionThe software does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources.
- CWE-331 - Insufficient EntropyThe software uses an algorithm or scheme that produces insufficient entropy, leaving patterns or clusters of values that are more likely to occur than others.
References