==========================================================================
Ubuntu Security Notice USN-7619-1
July 07, 2025

libssh vulnerabilities
==========================================================================

A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 25.04
- Ubuntu 24.10
- Ubuntu 24.04 LTS
- Ubuntu 22.04 LTS

Summary:

Several security issues were fixed in libssh.

Software Description:
- libssh: A tiny C SSH library

Details:

Ronald Crane discovered that libssh incorrectly handled certain base64
conversions. An attacker could use this issue to cause libssh to crash,
resulting in a denial of service, or possibly execute arbitrary code.
(CVE-2025-4877)

Ronald Crane discovered that libssh incorrectly handled the
privatekey_from_file() function. An attacker could use this issue to cause
libssh to crash, resulting in a denial of service, or possibly execute
arbitrary code. (CVE-2025-4878)

Ronald Crane discovered that libssh incorrectly handled certain memory
operations in the sftp server. An attacker could possibly use this issue
to cause libssh to crash, resulting in a denial of service.
(CVE-2025-5318, CVE-2025-5449)

Ronald Crane discovered that libssh incorrectly handled exporting keys. An
attacker could possibly use this issue to cause libssh to crash, resulting
in a denial of service. This issue only affected Ubuntu 24.04 LTS, Ubuntu
24.10, and Ubuntu 25.04. (CVE-2025-5351)

Ronald Crane discovered that libssh incorrectly handled the ssh_kdf()
function. An attacker could use this issue to cause libssh to crash,
resulting in a denial of service, or possibly execute arbitrary code.
(CVE-2025-5372)

Ronald Crane discovered that libssh incorrectly handled the ChaCha20
cipher. An attacker could possibly use this issue to cause libssh to
use partially initialized cypher content. This issue only affected Ubuntu
24.04 LTS, Ubuntu 24.10, and Ubuntu 25.04. (CVE-2025-5987)

Update instructions:

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 25.04
  libssh-4                        0.11.1-1ubuntu0.1

Ubuntu 24.10
  libssh-4                        0.10.6-3ubuntu1.1

Ubuntu 24.04 LTS
  libssh-4                        0.10.6-2ubuntu0.1

Ubuntu 22.04 LTS
  libssh-4                        0.9.6-2ubuntu0.22.04.4

In general, a standard system update will make all the necessary changes.

References:
  https://ubuntu.com/security/notices/USN-7619-1
  CVE-2025-4877, CVE-2025-4878, CVE-2025-5318, CVE-2025-5351,
  CVE-2025-5372, CVE-2025-5449, CVE-2025-5987

Package Information:
  https://launchpad.net/ubuntu/+source/libssh/0.11.1-1ubuntu0.1
  https://launchpad.net/ubuntu/+source/libssh/0.10.6-3ubuntu1.1
  https://launchpad.net/ubuntu/+source/libssh/0.10.6-2ubuntu0.1
  https://launchpad.net/ubuntu/+source/libssh/0.9.6-2ubuntu0.22.04.4