A flaw was found in the x/crypto/ssh go library. Applications and libraries that misuse the ServerConfig.PublicKeyCallback callback may be susceptible to an authorization bypass. For example, an attacker may send public keys A and B and authenticate with A. PublicKeyCallback would be called only twice, first with A and then with B. A vulnerable application may then make authorization decisions based on key B, for which the attacker does not control the private key. The misuse of ServerConfig.PublicKeyCallback may cause an authorization bypass.

A privilege escalation vulnerability was found in Sudo. In certain configurations, unauthorized users can gain elevated system privileges via the Sudo host option (`-h` or `--host`). When using the default sudo security policy plugin (sudoers), the host option is intended to be used in conjunction with the list option (`-l` or `--list`) to determine what permissions a user has on a different system. However, this restriction can be bypassed, allowing a user to elevate their privileges on one system to the privileges they may have on a different system, effectively ignoring the host identifier in any sudoers rules. This vulnerability is particularly impactful for systems that share a single sudoers configuration file across multiple computers or use network-based user directories, such as LDAP, to provide sudoers rules on a system.