GHSA-mf7q-r4rv-jv94
GHSA-mf7q-r4rv-jv94 is a security vulnerability in github.com/crossplane/crossplane-runtime/v2. O3 Security confirms whether GHSA-mf7q-r4rv-jv94 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Crossplane's TOCTOU between cosign verification and image fetch in xpkg.CachedClient allows tag-based package install to bypass signature check
Real-World Exposure
github.com/crossplane/crossplane-runtime/v2🐹github.com/crossplane/crossplane-runtime/v2Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Summary
Crossplane allows package signature verification to be configured via the ImageConfig mechanism. When enabled, the package manager uses cosign to verify that packages are correctly signed before pulling and installing them.
When a package is installed using a tag reference (e.g., a semantic version), a malicious OCI registry could serve a correctly signed image for verification, then subsequently serve an unsigned image for installation. This is possible because Crossplane resolves the tag reference separately for each step.
This vulnerability is relevant only for users who do all three of the following:
- Configure signature verification for packages,
- Install packages using tag references rather than digests, and
- Install packages from registries they do not control.
Mitigation
Installing packages by image digest rather than using tags avoids this issue.
Fix
The package manager has been updated to resolve tag references once and use the resulting digest for both signature verification and image fetching. This ensures that Crossplane pulls the same content that had its signature verified. The fix has been applied to Crossplane's main branch and backported to the v2.3 and v2.2 release branches; it will be released in v2.3.3 and v2.2.3.
Credits
This issue was reported, independently, by @bugbunny-research and @tonghuaroot.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/crossplane/crossplane-runtime/v2 | ≥ 2.4.0-rc.0&&< 2.4.0-rc.1 | 2.4.0-rc.1 |
| 🐹Go | github.com/crossplane/crossplane-runtime/v2 | ≥ 2.3.0&&< 2.3.3 | 2.3.3 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/crossplane/crossplane-runtime/v2. 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 github.com/crossplane/crossplane-runtime/v2 to 2.4.0-rc.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-mf7q-r4rv-jv94 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-mf7q-r4rv-jv94 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-mf7q-r4rv-jv94. 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-mf7q-r4rv-jv94 in your dependencies?
O3 detects GHSA-mf7q-r4rv-jv94 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.