CVE-2021-21273
Synapse is a Matrix reference homeserver written in python (pypi package matrix-synapse).
Does this matter?
Lower severity and a low EPSS score (1.81%). Track it; it rarely justifies an emergency change on its own.
Description
Synapse is a Matrix reference homeserver written in python (pypi package matrix-synapse). Matrix is an ecosystem for open federated Instant Messaging and VoIP. In Synapse before version 1.25.0, requests to user provided domains were not restricted to external IP addresses when calculating the key validity for third-party invite events and sending push notifications. This could cause Synapse to make requests to internal infrastructure. The type of request was not controlled by the user, although limited modification of request bodies was possible. For the most thorough protection server administrators should remove the deprecated `federation_ip_range_blacklist` from their settings after upgrading to Synapse v1.25.0 which will result in Synapse using the improved default IP address restrictions. See the new `ip_range_blacklist` and `ip_range_whitelist` settings if more specific control is necessary.
- CVSS 3.1
- 6.1 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
- EPSS
- 1.81% probability · 77th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-601
- Affected
- matrix/synapse · fedoraproject/fedora
- Source
- security-advisories@github.com
References
- https://github.com/matrix-org/synapse/commit/30fba6210834a4ecd91badf0c8f3eb278b72e746Patch, Third Party Advisory
- https://github.com/matrix-org/synapse/pull/8821Patch, Third Party Advisory
- https://github.com/matrix-org/synapse/releases/tag/v1.25.0Third Party Advisory
- https://github.com/matrix-org/synapse/security/advisories/GHSA-v936-j8gp-9q3pPatch, Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TNNAJOZNMVMXM6AS7RFFKB4QLUJ4IFEY/
- https://github.com/matrix-org/synapse/commit/30fba6210834a4ecd91badf0c8f3eb278b72e746Patch, Third Party Advisory
- https://github.com/matrix-org/synapse/pull/8821Patch, Third Party Advisory
- https://github.com/matrix-org/synapse/releases/tag/v1.25.0Third Party Advisory
- https://github.com/matrix-org/synapse/security/advisories/GHSA-v936-j8gp-9q3pPatch, Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TNNAJOZNMVMXM6AS7RFFKB4QLUJ4IFEY/
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.