CVE-2025-53945 is a high-severity (CVSS 7) Incorrect Default Permissions vulnerability in chainguard.dev/apko. A fix is available for chainguard.dev/apko — see the affected versions and patch details below.
apko has incorrect permission (0666) in /etc/ld.so.cache and other files
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-2025-53945.
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
chainguard.dev/apkoReal-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
It was discovered that the ld.so.cache in images generated by apko had file system permissions mode 0666:
bash-5.3# find / -type f -perm -o+w
/etc/ld.so.cache
This issue was introduced in commit 04f37e2 ("generate /etc/ld.so.cache (#1629)")(v0.27.0).
Impact
This potentially allows a local unprivileged user to add additional additional directories including dynamic libraries to the dynamic loader path. A user could exploit this by placing a malicious library in a directory they control.
Patches
This issue was addressed in apko in aedb077 ("fix: /etc/ld.so.cache file permissions (#1758)") (v0.29.5).
Acknowledgements
Many thanks to Cody Harris from H2O.ai for reporting this issue.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | chainguard.dev/apko | ≥ 0.27.0&&< 0.29.5 | 0.29.5go get chainguard.dev/apko@v0.29.5 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for chainguard.dev/apko, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update chainguard.dev/apko to 0.29.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-53945 is resolved across your whole dependency graph.
Workarounds
Close the privilege gap rather than the entry point: audit which accounts, roles and service identities can reach the affected operation, drop the component to the least privilege it actually needs, and review file and directory permissions created by earlier installs — a default left in place is what makes this reachable.
Frequently Asked Questions
Is CVE-2025-53945 in your dependencies?
Find it across Go, including transitive dependencies.