Cifs-utils: mount.cifs credential-file option injection allows local privilege boundary bypass
A flaw was found in cifs-utils. This flaw allows an unprivileged local user to achieve privilege escalation. When a privileged service mounts a Common Internet File System (CIFS) share using a user-controlled credentials file, input values are not properly sanitized before being assembled into mount options. A local attacker can exploit this vulnerability to inject unauthorized mount options, allowing them to bypass permission checks and execute files with administrative (root) privileges.
Cifs-utils: local privilege escalation via forged cifs.spnego key description in cifs.upcall
A flaw was found in the cifs-utils package where the cifs.upcall helper fails to securely drop its root privileges before looking up user information inside a user-controlled environment. A local, low privileged attacker can exploit this by using a crafted request_key payload to trick the root-owned helper into entering a custom environment (namespace) containing a malicious NSS module. This forces the system to load the attacker's controlled NSS Module and configuration, allowing them to execute arbitrary commands as the root user, elevating their privileges and fully compromising the system.
USN-7536-1 fixed vulnerabilities in cifs-utils. This update introduced a
regression in certain environments. This update fixes the problem.
We apologize for the inconvenience.
Original advisory details:
It was discovered that cifs-utils incorrectly handled namespaces when
obtaining Kerberos credentials. An attacker could possibly use this issue
to obtain sensitive information.
cifs.upcall makes an upcall to the wrong namespace in containerized environments
A flaw was found in cifs-utils. When trying to obtain Kerberos credentials, the cifs.upcall program from the cifs-utils package makes an upcall to the wrong namespace in containerized environments. This issue may lead to disclosing sensitive data from the host's Kerberos credentials cache.