Local Privilege Escalation in Sudo by Affected Users

CVE-2019-18684

Summary

A vulnerability in Sudo versions up to 1.8.29 enables local users with write access to file descriptor 3 to escalate their privileges to root. This occurs due to a race condition during the execution of uid determination and the setresuid and openat system calls. An attacker can exploit this vulnerability by writing specific configurations to /proc/#####/fd/3 while Sudo is waiting for a password prompt. While there is debate regarding the practical attack vectors given Linux /proc permissions, the potential for privilege escalation poses significant risks in environments where users have the necessary access.

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