GHSA-655h-hg88-5qmf
Rust XCB `xcb::Connection::connect_to_fd*` functions violate I/O safety
Blast Radius
xcbReal-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
The API of xcb::Connection has constructors which allow an arbitrary RawFd to be used as a socket connection. On either failure of these constructors or on the drop of Connection, it closes the associated file descriptor. Thus, a program which uses an OwnedFd (such as a UnixStream) as the file descriptor can close the file descriptor and continue to attempt using it or close an already-closed file descriptor, violating I/O safety.
Starting in version 1.6.0, xcb provides Connection::connect_with_fd and Connection::connect_with_fd_and_extensions as safe alternatives and deprecates the problematic functions.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | xcb | all versions | 1.6.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for xcb. 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 xcb to 1.6.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-655h-hg88-5qmf 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-655h-hg88-5qmf 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-655h-hg88-5qmf. 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-655h-hg88-5qmf in your dependencies?
O3 detects GHSA-655h-hg88-5qmf 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.