An issue was discovered in Dropbear through 2020.81. Due to a non-RFC-compliant check of the available authentication methods in the client-side SSH code, it is possible for an SSH server to change the login process in its favor. This attack can bypass additional security measures such as FIDO2 tokens or SSH-Askpass. Thus, it allows an attacker to abuse a forwarded agent for logging on to another server unnoticed.

WolfSSH v1.4.7 was discovered to contain an integer overflow via the function wolfSSH_SFTP_RecvRMDIR.

openssh_key_parser is an open source Python package providing utilities to parse and pack OpenSSH private and public key files. In versions prior to 0.0.6 if a field of a key is shorter than it is declared to be, the parser raises an error with a message containing the raw field value. An attacker able to modify the declared length of a key's sensitive field can thus expose the raw value of that field. Users are advised to upgrade to version 0.0.6, which no longer includes the raw field value in the error message. There are no known workarounds for this issue.

The addon.stdin service in addon-ssh (aka Home Assistant Community Add-on: SSH & Web Terminal) before 10.0.0 has an attack surface that requires social engineering. NOTE: the vendor does not agree that this is a vulnerability; however, addon.stdin was removed as a defense-in-depth measure against complex social engineering situations

A flaw has been found in libssh in versions prior to 0.9.6. The SSH protocol keeps track of two shared secrets during the lifetime of the session. One of them is called secret_hash and the other session_id. Initially, both of them are the same, but after key re-exchange, previous session_id is kept and used as an input to new secret_hash. Historically, both of these buffers had shared length variable, which worked as long as these buffers were same. But the key re-exchange operation can also change the key exchange method, which can be based on hash of different size, eventually creating "secret_hash" of different size than the session_id has. This becomes an issue when the session_id memory is zeroed or when it is used again during second key re-exchange.

SSH Tectia Client and Server before 6.4.19 on Windows allow local privilege escalation. ConnectSecure on Windows is affected.

SSH Tectia Client and Server before 6.4.19 on Windows allow local privilege escalation in nonstandard conditions. ConnectSecure on Windows is affected.

SSH Tectia Client and Server before 6.4.19 on Windows have weak key generation. ConnectSecure on Windows is affected.

scp.c in Dropbear before 2020.79 mishandles the filename of . or an empty filename, a related issue to CVE-2018-20685.

Dropbear 2011.54 through 2018.76 has an inconsistent failure delay that may lead to revealing valid usernames, a different issue than CVE-2018-15599.