Updated shadow-utils packages that fix a bug in pwconv are now available for Red Hat Enterprise Linux 5.
The shadow-utils package includes the necessary programs for converting UNIX password files to the shadow password format, plus programs for managing user and group accounts. The pwconv command converts passwords to the shadow password format. The pwunconv command converts shadow passwords and generates an npasswd file (a standard UNIX password file). The pwck command checks the integrity of password and shadow files. The lastlog command prints out the last login times for all users. The useradd, userdel, and usermod commands are used for managing user accounts. The groupadd, groupdel, and groupmod commands are used for managing group accounts.
A structural bug in a delete routine meant /etc/shadow (or /etc/gshadow) files containing bad entries were not updated properly by pwconv (or grpconv). Specifically if /etc/shadow (or /etc/gshadow) contained two consecutive bad entries, the second of the two bad entries was skipped when pwconv (or grpconv) was run on the file. This left the file improperly updated. With this update, the loop that iterates through /etc/shadow (or /etc/gshadow) was reworked. No bad lines (consecutive or otherwise) are now skipped and /etc/shadow (or /etc/gshadow) files are properly updated by pwconv (or grpconv).
All shadow-utils users should install this update which fixes this bug.