CVE-2023-0401
HIGHCVE-2023-0401 is a high-severity (CVSS 7.5) NULL Pointer Dereference vulnerability in openssl-src. O3 Security confirms whether CVE-2023-0401 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
NULL dereference during PKCS7 data verification
Blast Radius
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 NULL pointer can be dereferenced when signatures are being verified on PKCS7 signed or signedAndEnveloped data. In case the hash algorithm used for the signature is known to the OpenSSL library but the implementation of the hash algorithm is not available the digest initialization will fail. There is a missing check for the return value from the initialization function which later leads to invalid usage of the digest API most likely leading to a crash.
The unavailability of an algorithm can be caused by using FIPS enabled configuration of providers or more commonly by not loading the legacy provider.
PKCS7 data is processed by the SMIME library calls and also by the time stamp (TS) library calls. The TLS implementation in OpenSSL does not call these functions however third party applications would be affected if they call these functions to verify signatures on untrusted data.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | openssl-src | ≥ 300.0.0&&< 300.0.12 | 300.0.12 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for openssl-src. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
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-2023-0401 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2023-0401 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2023-0401. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2023-0401 in your dependencies?
O3 detects CVE-2023-0401 across crates.io dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.