URL deny list bypass via oEmbed and image URLs when generating previews in Synapse
Summary
URL deny list bypass via oEmbed and image URLs when generating previews in Synapse
Original description
The description as published by the source.
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: OSV.dev (Open Source Vulnerabilities) NVD GitHub Advisory OSV
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2023-32683 matrix-synapse Fixed in: 1.90.0-1
References
- advisory github.com
- advisory github.com
- advisory nvd.nist.gov
- patch github.com
- web lists.fedoraproject.org