Affected: Alpaquita:23: libssh2, Alpaquita:25: libssh2, Alpaquita:stream: libssh2

Affected: Homebrew: libssh2

libssh2 through 1.11.1 grows its publickey list with SSH2_REALLOC but does not zero-initialize new entries before parsing populates them, so a parse failure reaching the cleanup path leaves libssh2_publickey_list_free operating on an uninitialized entry. A malicious SSH server offering the publickey subsystem can use a malformed response to make cleanup free an uninitialized, attacker-influenceable attrs pointer in a connecting libssh2 client.

libssh2 through 1.11.1 grows its publickey list with SSH2_REALLOC but does not zero-initialize new entries before parsing populates them, so a parse failure reaching the cleanup path leaves libssh2_publickey_list_free operating on an uninitialized entry. A malicious SSH server offering the publickey subsystem can use a malformed response to make cleanup free an uninitialized, attacker-influenceable attrs pointer in a connecting libssh2 client.

libssh2 through 1.11.1 grows its publickey list with SSH2_REALLOC but does not zero-initialize new entries before parsing populates them, so a parse failure reaching the cleanup path leaves libssh2_publickey_list_free operating on an uninitialized entry. A malicious SSH server offering the publickey subsystem can use a malformed response to make cleanup free an uninitialized, attacker-influenceable attrs pointer in a connecting libssh2 client.

libssh2-1-1.11.1-4.1 on GA media

libssh2: libssh2: Denial of service or information disclosure via malformed SSH publickey response

Security update for libssh2_org

Affected: Ubuntu:Pro:14.04:LTS: libssh2, Ubuntu:Pro:16.04:LTS: libssh2, Ubuntu:Pro:18.04:LTS: libssh2, Ubuntu:Pro:20.04:LTS: libssh2, Ubuntu:22.04:LTS: libssh2, Ubuntu:24.04:LTS: libssh2, Ubuntu:25.10: libssh2, Ubuntu:26.04:LTS: libssh2

libssh2 through 1.11.1 grows its publickey list with SSH2_REALLOC but does not zero-initialize new entries before parsing populates them, so a parse failure reaching the cleanup path leaves libssh2_publickey_list_free operating on an uninitialized entry. A malicious SSH server offering the publickey subsystem can use a malformed response to make cleanup free an uninitialized, attacker-influenceable attrs pointer in a connecting libssh2 client.

Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in libssh2 ausnutzen, um Dateien zu manipulieren, Speicherbeschädigungen zu verursachen, einen Denial-of-Service-Zustand auszulösen oder andere, nicht näher spezifizierte Auswirkungen zu erzielen.