Synapse is a package for Matrix homeservers written in Python 3/Twisted. Prior to version 1.47.1, Synapse instances with the media repository enabled can be tricked into downloading a file from a remote server into an arbitrary directory. No authentication is required for the affected endpoint. The last 2 directories and file name of the path are chosen randomly by Synapse and cannot be controlled by an attacker, which limits the impact. Homeservers with the media repository disabled are unaffected. Homeservers with a federation whitelist are also unaffected, since Synapse will check the remote hostname, including the trailing `../`s, against the whitelist. Server administrators should upgrade to 1.47.1 or later. Server administrators using a reverse proxy could, at the expense of losing media functionality, may block the certain endpoints as a workaround. Alternatively, non-containerized deployments can be adapted to use the hardened systemd config.
References
Link | Resource |
---|---|
https://github.com/matrix-org/synapse/releases/tag/v1.47.1 | Release Notes Third Party Advisory |
https://github.com/matrix-org/synapse/security/advisories/GHSA-3hfw-x7gx-437c | Mitigation Third Party Advisory |
https://github.com/matrix-org/synapse/commit/91f2bd090 | Patch Third Party Advisory |
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/N3WY56LCEZ4ZECLWV5KMAXF2PSMUB4F2/ | Mailing List Third Party Advisory |
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/EU7QRE55U4IUEDLKT5IYPWL3UXMELFAS/ | Mailing List Third Party Advisory |
Information
Published : 2021-11-23 12:15
Updated : 2021-12-14 12:54
NVD link : CVE-2021-41281
Mitre link : CVE-2021-41281
JSON object : View
CWE
CWE-22
Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Products Affected
matrix
- synapse
fedoraproject
- fedora