CVE-2022-4203 — openssl-src
MEDIUMCVE-2022-4203 is a medium-severity (CVSS 4.9) Out-of-bounds Read vulnerability in openssl-src. A fix is available for openssl-src — see the affected versions and patch details below.
X.509 Name Constraints Read Buffer Overflow
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2022-4203.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
openssl-srcReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems.
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | openssl-src | ≥ 300.0.0&&< 300.0.12 | 300.0.12cargo update -p openssl-src --precise 300.0.12 |
Affected Products
opensslopensslDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for openssl-src, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update openssl-src to 300.0.12 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2022-4203 is resolved across your whole dependency graph.
Workarounds
Constrain what reaches the vulnerable code: limit the size and shape of untrusted input, isolate the affected component in a sandboxed or least-privileged process, and enable the platform's memory-safety mitigations (ASLR, stack protector, hardened allocator) so an out-of-bounds access is more likely to fail closed than to be exploitable.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
Red Hat Enterprise Linux 6, 7, and 8 ships OpenSSL 1.1.1 and 1.0.2 which do not contain the incorrect code, so those are not affected by this CVE. Similarly, the versions of `shim` as shipped with Red Hat Enterprise Linux 8 and 9 are not affected by this issue.
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Enterprise Linux 9 | openssl-1:3.0.1-47.el9_1 | RHSA-2023:0946 |
| Red Hat Enterprise Linux 9.0 Extended Update Support | openssl-1:3.0.1-46.el9_0 | RHSA-2023:1199 |
Frequently Asked Questions
Is CVE-2022-4203 in your dependencies?
Find it across crates.io, including transitive dependencies.