Overview
- Description
- Synapse is a Matrix protocol homeserver written in Python with the Twisted framework. A discovered oEmbed or image URL can bypass the `url_preview_url_blacklist` setting potentially allowing server side request forgery or bypassing network policies. Impact is limited to IP addresses allowed by the `url_preview_ip_range_blacklist` setting (by default this only allows public IPs) and by the limited information returned to the client: 1. For discovered oEmbed URLs, any non-JSON response or a JSON response which includes non-oEmbed information is discarded. 2. For discovered image URLs, any non-image response is discarded. Systems which have URL preview disabled (via the `url_preview_enabled` setting) or have not configured a `url_preview_url_blacklist` are not affected. This issue has been addressed in version 1.85.0. Users are advised to upgrade. User unable to upgrade may also disable URL previews.
- Source
- security-advisories@github.com
- NVD status
- Modified
Risk scores
CVSS 3.1
- Type
- Primary
- Base score
- 5.4
- Impact score
- 2.5
- Exploitability score
- 2.8
- Vector string
- CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
- Severity
- MEDIUM
Social media
- Hype score
- Not currently trending
Configurations
[
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:a:matrix:synapse:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "57D26682-77B5-428E-B7F8-50A0D2CB3C2E",
"versionEndExcluding": "1.85.0"
}
],
"operator": "OR"
}
]
}
]