CVE-2021-41281
CVSS V2 Medium 4.3
CVSS V3 High 7.5
Description
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.
Overview
- CVE ID
- CVE-2021-41281
- Assigner
- security-advisories@github.com
- Vulnerability Status
- Analyzed
- Published Version
- 2021-11-23T20:15:11
- Last Modified Date
- 2021-12-14T20:54:40
Weakness Enumerations
CPE Configuration (Product)
| CPE | Vulnerable | Operator | Version Start | Version End |
|---|---|---|---|---|
| cpe:2.3:a:matrix:synapse:*:*:*:*:*:*:*:* | 1 | OR | 1.47.1 | |
| cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:* | 1 | OR | ||
| cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:* | 1 | OR |
CVSS Version 2
- Version
- 2.0
- Vector String
- AV:N/AC:M/Au:N/C:N/I:P/A:N
- Access Vector
- NETWORK
- Access Compatibility
- MEDIUM
- Authentication
- NONE
- Confidentiality Impact
- NONE
- Integrity Impact
- PARTIAL
- Availability Impact
- NONE
- Base Score
- 4.3
- Severity
- MEDIUM
- Exploitability Score
- 8.6
- Impact Score
- 2.9
CVSS Version 3
- Version
- 3.1
- Vector String
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- Attack Vector
- NETWORK
- Attack Compatibility
- LOW
- Privileges Required
- NONE
- User Interaction
- NONE
- Scope
- UNCHANGED
- Confidentiality Impact
- NONE
- Availability Impact
- NONE
- Base Score
- 7.5
- Base Severity
- HIGH
- Exploitability Score
- 3.9
- Impact Score
- 3.6
References
| Reference URL | Reference Tags |
|---|---|
| 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 |
Sources
| Source Name | Source URL |
|---|---|
| NIST | https://nvd.nist.gov/vuln/detail/CVE-2021-41281 |
| MITRE | https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-41281 |
History
| Created | Old Value | New Value | Data Type | Notes |
|---|---|---|---|---|
| 2022-05-10 06:41:21 | Added to TrackCVE | |||
| 2022-12-05 15:06:57 | 2021-11-23T20:15Z | 2021-11-23T20:15:11 | CVE Published Date | updated |
| 2022-12-05 15:06:57 | 2021-12-14T20:54:40 | CVE Modified Date | updated | |
| 2022-12-05 15:06:57 | Analyzed | Vulnerability Status | updated |