In Sudo before 1.9.12p2, the sudoedit (aka -e) feature mishandles extra arguments passed in the user-provided environment variables (SUDO_EDITOR, VISUAL, and EDITOR), allowing a local attacker to append arbitrary entries to the list of files to process. This can lead to privilege escalation. Affected versions are 1.8.0 through 1.9.12.p1. The problem exists because a user-specified editor may contain a "--" argument that defeats a protection mechanism, e.g., an EDITOR='vim -- /path/to/extra/file' value.