CVE-2021-21273
Publication date 26 February 2021
Last updated 24 July 2024
Ubuntu priority
Cvss 3 Severity Score
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.
Status
Package | Ubuntu Release | Status |
---|---|---|
matrix-synapse | 24.10 oracular |
Not affected
|
24.04 LTS noble |
Not affected
|
|
22.04 LTS jammy |
Not affected
|
|
20.04 LTS focal |
Needs evaluation
|
|
18.04 LTS bionic |
Needs evaluation
|
|
16.04 LTS xenial | Not in release | |
14.04 LTS trusty | Not in release |
Severity score breakdown
Parameter | Value |
---|---|
Base score | 6.1 · Medium |
Attack vector | Network |
Attack complexity | Low |
Privileges required | None |
User interaction | Required |
Scope | Changed |
Confidentiality | Low |
Integrity impact | Low |
Availability impact | None |
Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
References
Other references
- https://github.com/matrix-org/synapse/security/advisories/GHSA-v936-j8gp-9q3p
- https://github.com/matrix-org/synapse/commit/30fba6210834a4ecd91badf0c8f3eb278b72e746
- https://github.com/matrix-org/synapse/pull/8821
- https://github.com/matrix-org/synapse/releases/tag/v1.25.0
- https://www.cve.org/CVERecord?id=CVE-2021-21273