SB2024010337 - Ubuntu update for openssh

Description

This security bulletin contains information about 3 secuirty vulnerabilities.

1) Improper Privilege Management (CVE-ID: CVE-2021-41617)

The vulnerability allows a local user to escalate privileges.

The vulnerability exists due to improper privilege management in sshd, when certain non-default configurations are used, because supplemental groups are not initialized as expected. Helper programs for AuthorizedKeysCommand and AuthorizedPrincipalsCommand may run with privileges associated with group memberships of the sshd process, if the configuration specifies running the command as a different user. A local user can escalate privileges on the system.

2) Inadequate Encryption Strength (CVE-ID: CVE-2023-51384)

The vulnerability allows a remote attacker to gain access to sensitive information.

The vulnerability exists due to an error in the ssh-agent, which causes certain destination constraints to be incompletely applied. When destination constraints are specified during addition of PKCS#11-hosted private keys, these constraints are only applied to the first key, even if a PKCS#11 token returns multiple keys.

3) OS Command Injection (CVE-ID: CVE-2023-51385)

The vulnerability allows a remote attacker to execute arbitrary shell commands on the target system.

The vulnerability exists due to improper input validation when processing user names, if a user name or host name has shell metacharacters, and this name is referenced by an expansion token in certain situations. A remote attacker can execute arbitrary OS commands via an untrusted Git repository.

Remediation

Install update from vendor's website.

References

• https://ubuntu.com/security/notices/USN-6565-1