The SSH transport protocol with certain OpenSSH extensions, found in OpenSSH before 9.6 and other products, allows remote attackers to bypass integrity checks such that some packets are omitted (from the extension negotiation message), and a client and server may consequently end up with a connection for which some security features have been downgraded or disabled, aka a Terrapin attack. This occurs because the SSH Binary Packet Protocol (BPP), implemented by these extensions, mishandles the handshake phase and mishandles use of sequence numbers. For example, there is an effective attack against SSH's use of ChaCha20-Poly1305 (and CBC with Encrypt-then-MAC). The bypass occurs in chacha20-poly1305@openssh.com and (if CBC is used) the -etm@openssh.com MAC algorithms. This also affects Maverick Synergy Java SSH API before 3.1.0-SNAPSHOT, Dropbear through 2022.83, Ssh before 5.1.1 in Erlang/OTP, PuTTY before 0.80, AsyncSSH before 2.14.2, golang.org/x/crypto before 0.17.0, libssh before 0…

An integer overflow flaw, which could lead to an out of bounds write, was discovered in libssh2 before 1.8.1 in the way keyboard prompt requests are parsed. A remote attacker who compromises a SSH server may be able to execute code on the client system when a user connects to the server.

An integer overflow flaw which could lead to an out of bounds write was discovered in libssh2 before 1.8.1 in the way SSH_MSG_CHANNEL_REQUEST packets with an exit signal are parsed. A remote attacker who compromises a SSH server may be able to execute code on the client system when a user connects to the server.

A flaw was found in libssh2 before 1.8.1. A server could send a multiple keyboard interactive response messages whose total length are greater than unsigned char max characters. This value is used as an index to copy memory causing in an out of bounds memory write error.

An integer overflow flaw which could lead to an out of bounds write was discovered in libssh2 before 1.8.1 in the way packets are read from the server. A remote attacker who compromises a SSH server may be able to execute code on the client system when a user connects to the server.

Format string vulnerability in the log function in Georgia SoftWorks SSH2 Server (GSW_SSHD) 7.01.0003 and earlier allows remote attackers to execute arbitrary code via format string specifiers in the username field, as demonstrated by a certain LoginPassword message.

Multiple buffer overflows in Georgia SoftWorks SSH2 Server (GSW_SSHD) 7.01.0003 and earlier allow remote attackers to execute arbitrary code via a (1) a long username, which triggers an overflow in the log function; or (2) a long password.