Ce mail provient de l'extérieur, restons vigilants

=====================================================================

                            CERT-Renater

                Note d'Information No. 2025/VULN765
_____________________________________________________________________

DATE                : 05/11/2025

HARDWARE PLATFORM(S): /

OPERATING SYSTEM(S): Systems running curl versions prior to 8.17.0.

=====================================================================
https://curl.se/docs/CVE-2025-10966.html
_____________________________________________________________________

CVE-2025-10966
missing SFTP host verification with wolfSSH

Project curl Security Advisory, November 5 2025 - Permalink


VULNERABILITY

curl's code for managing SSH connections when SFTP was done using the
wolfSSH powered backend was flawed and missed host verification
mechanisms.

This prevents curl from detecting MITM attackers and more.


INFO

curl contains support for several different SSH backends, out of
which wolfSSH is the newest and one that seems to almost never be
used. Of course partially because of its incomplete state. When
building curl, a single specific SSH backend is selected at
build-time.

The wolfSSH backend never supported SCP, only SFTP.

As the wolfSSH backend was documented to be incomplete and to fail
tests, we don't expect many users to use this code in production.

The missing known host support and host key verification for wolfSSH
were omissions from the time this code was added, as we expected and
hoped it would grow and get improved over time. As we never got bug
reports or comments on the code (which implies that nobody uses it)
it never triggered anyone to continue the improvements and complete
the implementation.

We have since introduced the concept of experimental features, and
should we have done this attempt today this code would probably
never have left the experimental state.

We have now completely removed support for wolfSSH.

The Common Vulnerabilities and Exposures (CVE) project has assigned
the name CVE-2025-10966 to this issue.

CWE-322: Key Exchange without Entity Authentication

Severity: Low


AFFECTED VERSIONS

    Affected versions: curl 7.69.0 to and including 8.16.0
    Not affected versions: curl < 7.69.0 and >= 8.16.0
    Introduced-in: https://github.com/curl/curl/commit/6773c7ca65cf2183295e56

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

This bug is not considered a C mistake. It is not likely to have been
avoided had we not been using C.

This flaw also affects the curl command line tool.


SOLUTION

Starting in curl 8.17.0, this mistake is fixed. Support for wolfSSH
is dropped.

    Fixed-in: https://github.com/curl/curl/commit/b011e3fcfb06d6c027859


RECOMMENDATIONS

A - Upgrade curl to version 8.17.0

B - Build curl with another SSH backend

C - Avoid using sftp://


TIMELINE

This issue was reported to the curl project on September 23, 2025.
We contacted distros@openwall on October 29, 2025.

curl 8.17.0 was released on November 5 2025 around 07:00 UTC,
coordinated with the publication of this advisory.

The curl security team is not aware of any active exploits using this
vulnerability.


CREDITS

    Reported-by: Stanislav Fort (Aisle Research)
    Patched-by: Daniel Stenberg


Thanks a lot!


=========================================================
+ CERT-RENATER        |    tel : 01-53-94-20-44         +
+ 23/25 Rue Daviel    |    fax : 01-53-94-20-41         +
+ 75013 Paris         |   email:cert@support.renater.fr +
=========================================================