HexBrain

Internet Bug Bounty · Report #1614331

CVE-2022-32207: Unpreserved file permissions

Validstatus
mediumseverity
$2,400bounty
7upvotes
27 Jun 2022disclosed

Summary

CVE-2022-32207: Unpreserved file permissions Project curl Security Advisory, June 27th 2022

VULNERABILITY 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.

We are not aware of any exploit of this flaw.

INFO CVE-2022-32207 was introduced in commit b834890a3fa3f52, shipped in curl 7.69.0.

This problem can be worked-around by using a strict umask.

CWE-281: Improper Preservation of Permissions

Severity: Medium

AFFECTED VERSIONS Affected versions: curl 7.69.0 to and including 7.83.1 Not affected versions: curl < 7.69.0 and curl >= 7.84.0 libcurl is used by many applications, but not always advertised as such!

THE SOLUTION A fix for CVE-2022-32207

RECOMMENDATIONS A - Upgrade curl to version 7.84.0

B - Apply the patch to your local version

C - Make extra precautions to protect saved files (ie strict umask)

TIMELINE 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.

CREDITS This issue was reported by Harry Sintonen. Patched by Daniel Stenberg.

Thanks a lot!

Security Advisory: https://curl.se/docs/CVE-2022-32207.html

How it was found

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.

Impact

Information disclosure (cookie file in specific)

This report was disclosed publicly on HackerOne and belongs to its author and the program. See the original