CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
LOW
Integrity Impact
LOW
Availability Impact
NONE
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
EPSS
Percentile
41.2%
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:
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.
The issue is fixed by #15601.
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.
github.com/advisories/GHSA-98px-6486-j7qc
github.com/matrix-org/synapse/pull/15601
github.com/matrix-org/synapse/releases/tag/v1.85.0
github.com/matrix-org/synapse/security/advisories/GHSA-98px-6486-j7qc
github.com/pypa/advisory-database/tree/main/vulns/matrix-synapse/PYSEC-2023-85.yaml
lists.fedoraproject.org/archives/list/[email protected]/message/X6DH5A5YEB5LRIPP32OUW25FCGZFCZU2
nvd.nist.gov/vuln/detail/CVE-2023-32683