Non-preserved file permissions
Project curl Security Advisory, June 27th 2022 - Permalink
When curl saves cookies, alt-svc and hsts data to local files, it makes the operation atomic by finalizing the operation with a rename from a temporary name to the final target file name.
In that rename operation, it might accidentally widen the permissions for the target file, leaving the updated file accessible to more users than intended.
This problem can be worked-around by using a strict umask.
CWE-281: Improper Preservation of Permissions
- Affected versions: curl 7.69.0 to and including 7.83.1
- Not affected versions: curl < 7.69.0 and curl >= 7.84.0
- Introduced-in: https://github.com/curl/curl/commit/b834890a3fa3f52
libcurl is used by many applications, but not always advertised as such!
A - Upgrade curl to version 7.84.0
B - Apply the patch to your local version
C - Make extra precautions to protect saved files (for example strict umask)
This issue was reported to the curl project on May 17, 2022. We contacted distros@openwall on June 20.
libcurl 7.84.0 was released on June 27 2022, coordinated with the publication of this advisory.
- Reported-by: Harry Sintonen
- Patched-by: Daniel Stenberg
Thanks a lot!