DEBIAN-CVE-2025-5372

A flaw was found in libssh versions built with OpenSSL versions older than 3.0, specifically in the ssh_kdf() function responsible for key derivation. Due to inconsistent interpretation of return values where OpenSSL uses 0 to indicate failure and libssh uses 0 for success—the function may mistakenly return a success status even when key derivation fails. This results in uninitialized cryptographic key buffers being used in subsequent communication, potentially compromising SSH sessions' confidentiality, integrity, and availability.

References

https://security-tracker.debian.org/tracker/CVE-2025-5372

Affected packages

Debian:11 / libssh

Package

Name: libssh
Purl: pkg:deb/debian/libssh?arch=source

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Fixed

0.9.8-0+deb11u2

Affected versions

0.*

0.9.5-1

0.9.5-1+deb11u1

0.9.6-1

0.9.6-2

0.9.7-0+deb11u1

0.9.8-0+deb11u1

Ecosystem specific

{
    "urgency": "not yet assigned"
}

Debian:12 / libssh

Package

Name: libssh
Purl: pkg:deb/debian/libssh?arch=source

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Affected versions

0.*

0.10.5-2

0.10.5-3

0.10.5-3+hurd.1

0.10.6-0+deb12u1

0.10.6-1

0.10.6-2

0.10.6-3

0.11.1-1

0.11.1-2

0.11.2-1

0.11.3-1

Ecosystem specific

{
    "urgency": "not yet assigned"
}

Debian:13 / libssh

Package

Name: libssh
Purl: pkg:deb/debian/libssh?arch=source

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Fixed

0.11.2-1

Ecosystem specific

{
    "urgency": "not yet assigned"
}

Debian:14 / libssh

Package

Name: libssh
Purl: pkg:deb/debian/libssh?arch=source

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Fixed

0.11.2-1

Ecosystem specific

{
    "urgency": "not yet assigned"
}