CVE-2018-16515 Matrix Synapse Improper Signature Validation

High 8.8 Published 18 Sep 2018 Updated 5 Aug 2024

Remote attackers can spoof events due to improper signature validation, compromising data integrity in Matrix Synapse deployments.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Over the internet
Victim action needed: Not needed
Fix: Available

What is CVE-2018-16515?

CVE-2018-16515 is a high-severity vulnerability in Debian Debian Linux, published on 18 Sep 2018. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

Matrix Synapse before 0.33.3.1 allows remote attackers to spoof events and possibly have unspecified other impacts by leveraging improper transaction and event signature validation.

Weakness: CWE-347

Which versions are affected by CVE-2018-16515?

5 open source packages ship an affected version, including matrix-synapse. It affects 2 products.

Package	Affected	Fixed in
`matrix-synapse` PyPI	All versions	`0.33.2.1, 0.33.3.1`
`matrix-synapse` PyPI	All versions	`0.33.2.1`
`matrix-synapse` PyPI	All versions	`0.33.2.1`
`matrix-synapse` PyPI	From `0.33.3`	`0.33.3.1`
`matrix-synapse` PyPI	From `0.33.3`	`0.33.3.1`

Products include Debian Debian Linux, Matrix Synapse.

How do I fix CVE-2018-16515?

Upgrade matrix-synapse to a fixed version for your release line: 0.33.2.1 or 0.33.3.1.

Is CVE-2018-16515 being exploited?

There is no known exploitation of CVE-2018-16515 in the wild and no public exploit code.

All Debian Debian Linux vulnerabilities

Sources

Also known as GHSA-fmvh-rvq5-hhjx, PYSEC-2026-845, UBUNTU-CVE-2018-16515.