cveboard RSS feed

CVE-2023-32683

CVE.org · Published

Historical CVEsJSONAI instructions

Record status
Published
Identifier year (not publication year)
2023
Source publication
Source updated
Imported by cveboard
Source snapshot
cve_2026-10-24_midnight_baseline ·

Plain text

CNA source text (English)

URL deny list bypass via oEmbed and image URLs when generating previews in Synapse

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.

Scoped product and version facts

Fix information unknown; no fixed version is derived here. Missing information does not prove that no fix exists.

Exploitation unknown; this catalogue does not assess exploitation.

synapse

Vendor
matrix-org
Product
synapse
Platforms
Unknown
Default status
Unknown
synapse · Scoped product and version facts
Version (version)Status (status)Version scheme (versionType)Exclusive end (lessThan)Inclusive end (lessThanOrEqual)Status changes (at → status)
< 1.85.0affectedUnavailableUnavailableUnavailableNone listed