Bugzilla – Bug 1212055
VUL-0: CVE-2023-32683: matrix-synapse: URL deny list bypass via oEmbed and image URLs when generating previews
Last modified: 2023-07-07 10:35:07 UTC
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. reference: https://github.com/matrix-org/synapse/releases/tag/v1.85.0 https://github.com/matrix-org/synapse/security/advisories/GHSA-98px-6486-j7qc
This is an autogenerated message for OBS integration: This bug (1212055) was mentioned in https://build.opensuse.org/request/show/1097110 Factory / matrix-synapse