GHSA-wfg4-322g-9vqv
memoffset allows reading uninitialized memory
Blast Radius
memoffsetReal-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
memoffset allows attempt of reading data from address 0 with arbitrary type. This behavior is an undefined behavior because address 0 to std::mem::size_of<T> may not have valid bit-pattern with T. Old implementation dereferences uninitialized memory obtained from std::mem::align_of. Older implementation prior to it allows using uninitialized data obtained from std::mem::uninitialized with arbitrary type then compute offset by taking the address of field-projection. This may also result in an undefined behavior for "father" that includes (directly or transitively) type that does not allow to be uninitialized.
This flaw was corrected by using std::ptr::addr_of in https://github.com/Gilnaa/memoffset/pull/50.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | memoffset | all versions | 0.6.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for memoffset. 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 memoffset to 0.6.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-wfg4-322g-9vqv 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 GHSA-wfg4-322g-9vqv 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 GHSA-wfg4-322g-9vqv. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-wfg4-322g-9vqv in your dependencies?
O3 detects GHSA-wfg4-322g-9vqv 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.