[SECURITY ADVISORY] curl: HSTS long file name clears contents

[Daniel Stenberg <daniel () haxx se>]

HSTS long file name clears contents
===================================

Project curl Security Advisory, December 6 2023 -
[Permalink](https://curl.se/docs/CVE-2023-46219.html)

VULNERABILITY
-------------

When saving HSTS data to an excessively long file name, curl could end up
removing all contents, making subsequent requests using that file unaware of
the HSTS status they should otherwise use.

INFO
----

The reason for this bug is that save function appended a suffix to the file
name, created a temporary file and then in the last step renamed that to the
final name. When the file name length was close to the limit of what is
allowed on the file system, adding the extension would make it too long and
then trigger this bug.

The Common Vulnerabilities and Exposures (CVE) project has assigned the name
CVE-2023-46219 to this issue.

CWE-311: Missing Encryption of Sensitive Data

Severity: Low

AFFECTED VERSIONS
-----------------

- Affected versions: curl 7.84.0 to and including 8.4.0
- Not affected versions: curl < 7.84.0 and >= 8.5.0
- Introduced-in: https://github.com/curl/curl/commit/20f9dd6bae50b722

libcurl is used by many applications, but not always advertised as such!

This flaw is also accessible using the curl command line tool.

SOLUTION
------------

Starting in curl 8.5.0, the temporary file name made done using a pure random
sequence of letters instead of being based on the original.

- Fixed-in: https://github.com/curl/curl/commit/73b65e94f3531179de45

RECOMMENDATIONS
--------------

 A - Upgrade curl to version 8.5.0

 B - Apply the patch to your local version

 C - Do not use HSTS

TIMELINE
--------

This issue was reported to the curl project on November 2, 2023. We contacted
distros@openwall on November 28, 2023.

curl 8.5.0 was released on December 6 2023, coordinated with the publication
of this advisory.

CREDITS
-------

- Reported-by: Maksymilian Arciemowicz
- Patched-by: Daniel Stenberg

Thanks a lot!

--

 / daniel.haxx.se