CVE-2021-29471
Denial of service attack via push rule patterns in matrix-synapse
描述
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.
如何修補 CVE-2021-29471
要修補 CVE-2021-29471,請將受影響套件升級到下列已修補版本。
- —升級至 1.33.2 或更新版本
CVE-2021-29471 正在被利用嗎?
低 — EPSS 為 1.6%,目前沒有觀察到大規模利用活動。
受影響套件(1)
- from 0, < 1.33.2
CVSS 分數
| 來源 | 版本 | 嚴重程度 | 向量 |
|---|---|---|---|
| osv | CVSS 4.0 | — | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N |
| osv | CVSS 3.1 | LOW3.7 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L |