Distribution advisory
This page covers CVE-2023-42453 as tracked by Ubuntu, for the package matrix-synapse. The fix is available in version 1.53.0-1ubuntu0.1~esm2; earlier versions remain affected.
How this vulnerability can be exploited
This issue can be reached over the network, attack complexity is low, an attacker needs low-level privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality none, integrity low, availability none.
CVSS metrics in full
The score comes from this vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
- Attack vector: Network — reachable from anywhere that can route to the service.
- Attack complexity: Low — the attack works reliably, with no preparation.
- Privileges required: Low — an ordinary user account is enough.
- User interaction: None — nobody has to be tricked into anything.
- Scope: Unchanged — the damage stays inside the vulnerable component.
- Confidentiality impact: None.
- Integrity impact: Low — limited, and the attacker does not choose what is affected.
- Availability impact: None.
Weakness class
UBUNTU-CVE-2023-42453 is classified as CWE-285: Improper Authorization. A request is carried out without confirming that the caller is permitted to perform it on that specific resource.
Affected software
UBUNTU-CVE-2023-42453 is recorded against 1 package.
- matrix-synapse (fixed in 1.53.0-1ubuntu0.1~esm2)
Timeline and source
Published on 27 September 2023 and last revised on 4 February 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.
References
ubuntu.com (Report)
github.com (Report)
github.com (Report)
www.cve.org (Report)
ubuntu.com (Advisory)
Other advisories for this package
matrix-synapse has other advisories on record. If you are patching this one, these are worth checking on the same host:
Same weakness in other software
These advisories are the same class of weakness (CWE-285: Improper Authorization) in other software:
