apko is vulnerable to attack through incorrect permissions in /etc/ld.so.cache and other files
Date: 2025-07
Affected: go/chainguard.dev/apko
Attack vector: other
Category: vulnerability-disclosure
Severity: High
CVE: CVE-2025-53945
CWE: CWE-276
CVSS: 7 (CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:L)

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)")](https://github.com/chainguard-dev/apko/commit/04f37e2d50d5a502e155788561fb7d40de705bd9)([v0.27.0](https://github.com/chainguard-dev/apko/releases/tag/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)")](https://github.com/chainguard-dev/apko/commit/aedb0772d6bf6e74d8f17690946dbc791d0f6af3) ([v0.29.5](https://github.com/chainguard-dev/apko/releases/tag/v0.29.5)). ### Acknowledgements Many thanks to Cody Harris from [H2O.ai](http://h2o.ai/) for reporting this issue.


Mitigations:

Architectural layers (MAESTRO):