CVE-2023-32683
June 06, 2023
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.
Affected Packages
matrix-synapse (PYTHON):
Affected version(s) Fix Suggestion:
Update to version 1.85.0Related Resources (8)
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Contact UsCVSS v4
Base Score:
5.1
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
LOW
User Interaction
PASSIVE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
LOW
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
3.5
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
NONE
Integrity
LOW
Availability
NONE
EPSS
Base Score:
0.25
