A vulnerability in the setup package used by Red Hat Enterprise Linux could allow a local attacker to gain unauthorized access to a targeted system.
The vulnerability exists because the affected software adds /sbin/nologin and /usr/sbin/nologin to /etc/shells. As a result, pam_shells and some daemons that allow access based on a user's shell being listed in /etc/shells could be accessed without proper authorization. An attacker could exploit this vulnerability by sending a request that submits malicious input to the targeted system. A successful exploit could allow the attacker to gain unauthorized access to the system, which could be used to conduct further attacks.
The Setup Project confirmed the vulnerability and released software updates.
To exploit this vulnerability, the attacker must have user-level access to the targeted system. This access requirement may reduce the likelihood of a successful exploit.
Administrators are advised to apply the appropriate updates.
Administrators are advised to allow only trusted users to access local systems.
Administrators are advised to allow only privileged users to access administration or management systems.
Administrators are advised to monitor critical systems.
The Setup Project released a git commit at the following link: commit 7d94bb1
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