CVE-2021-41281
published 2021-11-23CVE-2021-41281: 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…
PriorityP347high7.5CVSS 3.1
AVNACLPRNUINSUCNIHAN
EPSS
1.51%
71.7th percentile
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.
Affected
5 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | matrix-synapse | < matrix-synapse 1.47.1-1 (forky) | matrix-synapse 1.47.1-1 (forky) |
| fedoraproject | fedora | — | — |
| fedoraproject | fedora | — | — |
| matrix-org | synapse | < 1.47.1 | 1.47.1 |
| matrix | synapse | < 1.47.1 | 1.47.1 |
CVSS provenance
nvdv3.17.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
nvdv2.04.3MEDIUMAV:N/AC:M/Au:N/C:N/I:P/A:N
osv7.5HIGH
vendor_debian7.5HIGH
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GHSA
Path traversal in Matrix Synapse
ghsa·2021-11-23
CVE-2021-41281 [HIGH] CWE-22 Path traversal in Matrix Synapse
Path traversal in Matrix Synapse
### Impact
Synapse instances with the media repository enabled can be tricked into downloading a file from a remote server into an arbitrary directory, potentially outside the media store directory.
The last two 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 configured with a federation whitelist are also unaffected.
### Patches
Server administrators should upgrade to 1.47.1 or later.
### Workarounds
Server administrators using a reverse proxy could, at the expense of losing media functionality, block the following endpoints:
* `/_matrix/media/r0/download/{serverName}/{mediaId}`
* `/_matrix
OSV
CVE-2021-41281: Synapse is a package for Matrix homeservers written in Python 3/Twisted
osv·2021-11-23·CVSS 7.5
CVE-2021-41281 [HIGH] CVE-2021-41281: Synapse is a package for Matrix homeservers written in Python 3/Twisted
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 m
OSV
Path traversal in Matrix Synapse
osv·2021-11-23
CVE-2021-41281 [HIGH] Path traversal in Matrix Synapse
Path traversal in Matrix Synapse
### Impact
Synapse instances with the media repository enabled can be tricked into downloading a file from a remote server into an arbitrary directory, potentially outside the media store directory.
The last two 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 configured with a federation whitelist are also unaffected.
### Patches
Server administrators should upgrade to 1.47.1 or later.
### Workarounds
Server administrators using a reverse proxy could, at the expense of losing media functionality, block the following endpoints:
* `/_matrix/media/r0/download/{serverName}/{mediaId}`
* `/_matrix
Debian
CVE-2021-41281: matrix-synapse - Synapse is a package for Matrix homeservers written in Python 3/Twisted. Prior t...
vendor_debian·2021·CVSS 7.5
CVE-2021-41281 [HIGH] CVE-2021-41281: matrix-synapse - Synapse is a package for Matrix homeservers written in Python 3/Twisted. Prior t...
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 m
No detection rules found.
No public exploits indexed.
No writeups or analysis indexed.
https://github.com/matrix-org/synapse/commit/91f2bd090https://github.com/matrix-org/synapse/releases/tag/v1.47.1https://github.com/matrix-org/synapse/security/advisories/GHSA-3hfw-x7gx-437chttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EU7QRE55U4IUEDLKT5IYPWL3UXMELFAS/https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/N3WY56LCEZ4ZECLWV5KMAXF2PSMUB4F2/https://github.com/matrix-org/synapse/commit/91f2bd090https://github.com/matrix-org/synapse/releases/tag/v1.47.1https://github.com/matrix-org/synapse/security/advisories/GHSA-3hfw-x7gx-437chttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EU7QRE55U4IUEDLKT5IYPWL3UXMELFAS/https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/N3WY56LCEZ4ZECLWV5KMAXF2PSMUB4F2/
2021-11-23
Published