Running sudo 1.7.4p6 on Mac OS X 10.7.5, the SUDO_UID environment variable truncates the last digit of any user's UID which is larger than or equal to 1 billion (1_000_000_000).

I downloaded the sudo 1.8.8 source and confirmed plugins/sudoers/env.c copies the UID to a fixed-size buffer.

The autoconf default size of this buffer is 10 bytes (9 bytes of string plus 1 byte for NUL), so UIDs larger than 1_000_000_000 like the following are truncated.

I think this should change to use a dynamically-sized buffer to fit UIDs of any length.

$ sudo -V
Sudo version 1.7.4p6

$ id
uid=1230086403(username) gid=[snip] groups=[snip]

$ sudo sh -c 'echo $SUDO_UID'
Password:
123008640