An issue was discovered in OpenSSH 7.9. Due to the scp implementation being derived from 1983 rcp, the server chooses which files/directories are sent to the client. However, the scp client only performs cursory validation of the object name returned (only directory traversal attacks are prevented). A malicious scp server (or Man-in-The-Middle attacker) can overwrite arbitrary files in the scp client target directory. If recursive operation (-r) is performed, the server can manipulate subdirectories as well (for example, to overwrite the .ssh/authorized_keys file).

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…

Like many other SSH implementations, Apache MINA SSHD suffered from the issue that is more widely known as CVE-2023-48795. An attacker that can intercept traffic between client and server could drop certain packets from the stream, potentially causing client and server to consequently end up with a connection for which some security features have been downgraded or disabled, aka a Terrapin attack The mitigations to prevent this type of attack were implemented in Apache MINA SSHD 2.12.0, both client and server side. Users are recommended to upgrade to at least this version. Note that both the client and the server implementation must have mitigations applied against this issue, otherwise the connection may still be affected.

A vulnerability was found in ProSSHD 1.2 on Windows. It has been declared as problematic. This vulnerability affects unknown code. The manipulation leads to denial of service. The attack can be initiated remotely. The exploit has been disclosed to the public and may be used. The identifier of this vulnerability is VDB-251548.

A vulnerability was found in freeSSHd 1.0.9 on Windows. It has been classified as problematic. This affects an unknown part. The manipulation leads to denial of service. It is possible to initiate the attack remotely. The exploit has been disclosed to the public and may be used. The associated identifier of this vulnerability is VDB-251547.

Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Apache Software Foundation Apache MINA. In SFTP servers implemented using Apache MINA SSHD that use a RootedFileSystem, logged users may be able to discover "exists/does not exist" information about items outside the rooted tree via paths including parent navigation ("..") beyond the root, or involving symlinks. This issue affects Apache MINA: from 1.0 before 2.10. Users are recommended to upgrade to 2.10

Class org.apache.sshd.server.keyprovider.SimpleGeneratorHostKeyProvider in Apache MINA SSHD <= 2.9.1 uses Java deserialization to load a serialized java.security.PrivateKey. The class is one of several implementations that an implementor using Apache MINA SSHD can choose for loading the host keys of an SSH server.

A vulnerability in sshd-core of Apache Mina SSHD allows an attacker to overflow the server causing an OutOfMemory error. This issue affects the SFTP and port forwarding features of Apache Mina SSHD version 2.0.0 and later versions. It was addressed in Apache Mina SSHD 2.7.0

Insecure access control in freeSSHd version 1.3.1 allows attackers to obtain the privileges of the freesshd.exe process by leveraging the ability to login to an unprivileged account on the server.

FreeSSHd 1.3.1 version is vulnerable to an Unquoted Path Service allowing local users to launch processes with elevated privileges.