Comment 29 for bug 160862

Rationale for SRU: discussed with Chris Coulson on IRC, since the patch is only one line, it's worth backporting to Hardy, Jaunty and Karmic. Intrepid is too close to end of life. This bug destroys the system from the point of view of most users, since it completely prevents from logging in. The origin of the additional ':' is not identified, but this seems to have affected a significant number of people (see Ubuntu forums).

Patch doesn't bring a large risk, since it simply limits the number of fields we read from a line to the expected number, forcing everything else to be considered as usernames, which is harmless in case it's not correct. See
http://git.gnome.org/browse/system-tools-backends-clone/commit/?id=5bad3f88f5e28fd9c1b62e1da6ff062d520ccc61