CVE-2021-29471
Published May 11, 2021
Last updated a year ago
Overview
- Description
- 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.
- Source
- security-advisories@github.com
- NVD status
- Modified
Social media
- Hype score
- Not currently trending
Risk scores
CVSS 3.1
- Type
- Primary
- Base score
- 5.3
- Impact score
- 1.4
- Exploitability score
- 3.9
- Vector string
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
- Severity
- MEDIUM
CVSS 2.0
- Type
- Primary
- Base score
- 5
- Impact score
- 2.9
- Exploitability score
- 10
- Vector string
- AV:N/AC:L/Au:N/C:N/I:N/A:P
Configurations
[
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:a:matrix:synapse:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "CA3C30EA-7826-48F6-9367-5632BE392B50",
"versionEndExcluding": "1.33.2"
}
],
"operator": "OR"
}
]
},
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "A930E247-0B43-43CB-98FF-6CE7B8189835"
}
],
"operator": "OR"
}
]
}
]