The problem can be corrected by upgrading the affected package to
version 2:10.0-5ubuntu0.3 (for Ubuntu 4.10), 2:10.0-8ubuntu0.3 (for
Ubuntu 5.04), or 2:10.0-8ubuntu1.2 (for Ubuntu 5.10). In general, a
standard system upgrade is sufficient to effect the necessary changes.
Two buffer overflows were discovered in the 'pnmtopng' tool, which
were triggered by processing an image with exactly 256 colors when
using the -alpha option (CVE-2005-3662) or by processing a text file
with very long lines when using the -text option (CVE-2005-3632).
A remote attacker could exploit these to execute arbitrary code by
tricking an user or an automated system into processing a specially
crafted PNM file with pnmtopng.