CVE-2018-12291 Matrix Synapse Security Filtering Flaw
Attackers can view unauthorized events via the federation API due to incorrect visibility rule enforcement in Matrix Synapse.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2018-12291?
CVE-2018-12291 is a high-severity vulnerability in n/a, published on 13 Jun 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
The on_get_missing_events function in handlers/federation.py in Matrix Synapse before 0.31.1 has a security bug in the get_missing_events federation API where event visibility rules were not applied correctly.
Which versions are affected by CVE-2018-12291?
3 open source packages ship an affected version, including matrix-synapse. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
matrix-synapse PyPI | All versions | 0.31.1 |
matrix-synapse PyPI | All versions | 0.31.1 |
matrix-synapse PyPI | All versions | 0.31.1 |
Products include Matrix Synapse.
How do I fix CVE-2018-12291?
Upgrade matrix-synapse to 0.31.1 or later.
Is CVE-2018-12291 being exploited?
There is no known exploitation of CVE-2018-12291 in the wild and no public exploit code.
Other vulnerabilities in n/a
- CVE-2019-18835 Improper Verification of Cryptographic Signature in matrix-synapse
- CVE-2024-52815 Synapse allows a a malformed invite to break the invitee's `/sync`
- CVE-2024-52805 Synapse allows unsupported content types to lead to memory exhaustion
- CVE-2024-53863 Synapse can be forced to thumbnail unexpected file formats, invoking external, potentially untrustworthy decoders
- CVE-2024-37302 Synapse denial of service through media disk space consumption
Sources
Also known as GHSA-v8wm-g9f2-xjv4, PYSEC-2026-664, UBUNTU-CVE-2018-12291.