CVE-2023-32683 – matrix-synapse

Package

Manager: pip
Name: matrix-synapse
Vulnerable Version: >=0 <1.85.0

Severity

Level: Medium

CVSS v3.1: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N

CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N

EPSS: 0.00251 pctl0.48336

Details

Synapse has URL deny list bypass via oEmbed and image URLs when generating previews ### Impact 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: * For discovered oEmbed URLs, any non-JSON response or a JSON response which includes non-oEmbed information is discarded. * 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. Because of the uncommon configuration required, the limited information a malicious user, and the amount of guesses/time the attack would need; the severity is rated as low. ### Patches The issue is fixed by #15601. ### Workarounds The default configuration of the `url_preview_ip_range_blacklist` should protect against requests being made to internal infrastructure, URL previews of public URLs is expected. Alternately URL previews could be disabled using the `url_preview_enabled` setting.

Metadata

Created: 2023-06-06T16:41:34Z
Modified: 2024-09-30T20:34:41Z
Source: https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2023/06/GHSA-98px-6486-j7qc/GHSA-98px-6486-j7qc.json
CWE IDs: ["CWE-863", "CWE-918"]
Alternative ID: GHSA-98px-6486-j7qc
Finding: F100
Auto approve: 1