Vulnerability · Published Dec 3, 2024 · Assigned by GitHub_M
CVE-2024-37302Synapse denial of service through media disk space consumption
High 7.5
In plain English
A high-severity resource allocation without limits in synapse from element-hq. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 49% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Synapse is an open-source Matrix homeserver. Synapse versions before 1.106 are vulnerable to a disk fill attack, where an unauthenticated adversary can induce Synapse to download and cache large amounts of remote media. The default rate limit strategy is insufficient to mitigate this. This can lead to a denial of service, ranging from further media uploads/downloads failing to completely unavailability of the Synapse process, depending on how Synapse was deployed. Synapse 1.106 introduces a new "leaky bucket" rate limit on remote media downloads to reduce the amount of data a user can request at a time. This does not fully address the issue, but does limit an unauthenticated user's ability to request large amounts of data to be cached.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.20 | synapse | 1.110.0-r0 | ALPINE-CVE-2024-37302 |
| Alpine:v3.21 | synapse | 1.110.0-r0 | ALPINE-CVE-2024-37302 |
| Alpine:v3.22 | synapse | 1.110.0-r0 | ALPINE-CVE-2024-37302 |
| Alpine:v3.23 | synapse | 1.110.0-r0 | ALPINE-CVE-2024-37302 |
| Alpine:v3.24 | synapse | 1.110.0-r0 | ALPINE-CVE-2024-37302 |
| Debian:14 | matrix-synapse | 1.116.0-1 | DEBIAN-CVE-2024-37302 |
| PyPI | matrix-synapse | 1.106 | GHSA-4mhg-xv73-xq2x |
| PyPI | matrix-synapse | 1.106.0 | PYSEC-2024-286 |
| Ubuntu:24.04:LTS | matrix-synapse | no fix listed | UBUNTU-CVE-2024-37302 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| element-hq | synapse | < 1.106 |
Weakness: CWE-770 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
References
- https://github.com/element-hq/synapse/security/advisories/GHSA-4mhg-xv73-xq2x x_refsource_CONFIRM