CVE-2022-4203 X.509 Name Constraints Read Buffer Overflow
A buffer overrun in OpenSSL's X.509 name constraint checking allows attackers to cause denial of service or potentially disclose memory contents.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2022-4203?
CVE-2022-4203 is a medium-severity memory corruption vulnerability in Openssl Openssl, published on 24 Feb 2023. An attacker needs administrator access to exploit it, with no action from the victim.
Official description
A read buffer overrun can be triggered in X.509 certificate verification, specifically in name constraint checking. Note that this occurs after certificate chain signature verification and requires either a CA to have signed the malicious certificate or for the application to continue certificate verification despite failure to construct a path to a trusted issuer.
The read buffer overrun might result in a crash which could lead to a denial of service attack. In theory it could also result in the disclosure of private memory contents (such as private keys, or sensitive plaintext) although we are not aware of any working exploit leading to memory contents disclosure as of the time of release of this advisory.
In a TLS client, this can be triggered by connecting to a malicious server. In a TLS server, this can be triggered if the server requests client authentication and a malicious client connects.
Weakness: CWE-125
Which versions are affected by CVE-2022-4203?
3 open source packages ship an affected version, including openssl-src. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
openssl-src crates.io | From 300.0.0 | 300.0.12 |
openssl-src crates.io | From 300.0.0 | 300.0.12 |
openssl-src crates.io | From 300.0.0 | 300.0.12 |
Products include Openssl Openssl.
How do I fix CVE-2022-4203?
Upgrade openssl-src to 300.0.12 or later.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2022-4203 being exploited?
There is no known exploitation of CVE-2022-4203 in the wild and no public exploit code.
Other vulnerabilities in Openssl Openssl
Sources
Also known as ALPINE-CVE-2022-4203, CLEANSTART-2026-GM39950, DEBIAN-CVE-2022-4203, GHSA-w67w-mw4j-8qrv, RUSTSEC-2023-0008, UBUNTU-CVE-2022-4203.