Описание
Denial of service attack via push rule patterns in matrix-synapse
Impact
"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.
Patches
The issue is patched by https://github.com/matrix-org/synapse/commit/03318a766cac9f8b053db2214d9c332a977d226c.
Workarounds
A potential workaround might be to prevent users from making custom push rules, by blocking such requests at a reverse-proxy.
For more information
If you have any questions or comments about this advisory, email us at security@matrix.org.
Ссылки
- https://github.com/matrix-org/synapse/security/advisories/GHSA-x345-32rc-8h85
- https://nvd.nist.gov/vuln/detail/CVE-2021-29471
- https://github.com/matrix-org/synapse/commit/03318a766cac9f8b053db2214d9c332a977d226c
- https://github.com/matrix-org/synapse/releases/tag/v1.33.2
- https://github.com/pypa/advisory-database/tree/main/vulns/matrix-synapse/PYSEC-2021-135.yaml
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/TNNAJOZNMVMXM6AS7RFFKB4QLUJ4IFEY
Пакеты
matrix-synapse
< 1.33.2
1.33.2
EPSS
6.3 Medium
CVSS4
3.7 Low
CVSS3
CVE ID
Дефекты
Связанные уязвимости
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.
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.
Synapse is a Matrix reference homeserver written in python (pypi packa ...
Уязвимость правил push домашнего сервера Synapse, связанная с неконтролируемым расходом ресурсов, позволяющая нарушителю вызвать отказ в обслуживании
EPSS
6.3 Medium
CVSS4
3.7 Low
CVSS3