ELA-1592-1 libssh security update

multiple vulnerabilities

2025-12-10
Packagelibssh
Version0.7.3-2+deb9u5 (stretch)
Related CVEs CVE-2023-6004 CVE-2025-4877 CVE-2025-4878 CVE-2025-5318 CVE-2025-8114 CVE-2025-8277


Several vulnerabilities have been found in libssh, a tiny C SSH library.

CVE-2023-6004

Vinci found a command injection issue in the ProxyCommand and ProxyJump
features.

CVE-2025-4877

Ronald Crane found that bin_to_base64() could experience an integer
overflow and subsequent under allocation, leading to an out of
bounds write on 32-bit builds.

CVE-2025-4878

Ronald Crane found that privatekey_from_file() used an uninitialized
variable under certain conditions, which could lead to signing
failure, use-after-free or memory corruption.

CVE-2025-5318

Ronald Crane found that sftp_handle() had an incorrect check, which
could lead to an out of bounds read.

CVE-2025-8114

Philippe Antoine found a null pointer dereference issue when libssh
calculates the session id for the key exchange (KEX) process and an
error happens when allocating memory using cryptographic functions,
leading to a crash.

CVE-2025-8277

Francesco Rollo a memory leak during the KEX process when a client
sets the `first_kex_packet_follows` flag in the KEXINIT message and
repeatedly makes incorrect KEX guesses.


For Debian 9 stretch, these problems have been fixed in version 0.7.3-2+deb9u5.

We recommend that you upgrade your libssh packages.

Further information about Extended LTS security advisories can be found in the dedicated section of our website.