CVE-2022-35260: .netrc parser out-of-bounds access
Project curl Security Advisory, October 26 2022 - Permalink
VULNERABILITY
curl can be told to parse a .netrc
file for credentials. If that file ends in a line with consecutive non-white space letters and no newline, curl could read past the end of the stack-based buffer, and if the read works, write a zero byte possibly beyond its boundary.
This will in most cases cause a segfault or similar, but circumstances might also cause different outcomes.
If a malicious user can provide a custom netrc file to an application or otherwise affect its contents, this flaw could be used as denial-of-service.
We are not aware of any exploit of this flaw.
INFO
The flaw was introduced in curl with this commit, first shipped in curl 7.84.0.
The Common Vulnerabilities and Exposures (CVE) project has assigned the name CVE-2022-35260 to this issue.
CWE-121: Stack-based Buffer Overflow
Severity: low
AFFECTED VERSIONS
- Affected versions: curl 7.84.0 to and including 7.85.0
- Not affected versions: curl < 7.84.0 and >= 7.86.0
libcurl is used by many applications, but not always advertised as such!
THE SOLUTION
RECOMMENDATIONS
A - Upgrade curl to version 7.86.0
B - Apply the patch to your local version
C - Do not use .netrc
files
TIMELINE
This issue was reported to the curl project on October 3, 2022. We contacted distros@openwall on October 18, 2022.
libcurl 7.86.0 was released on October 26 2022, coordinated with the publication of this advisory.
CREDITS
- Reported-by: Hiroki Kurosawa
- Patched-by: Daniel Stenberg
Thanks a lot!