enscript is a powerful ASCII to PostScript file converter.
Erik Sjolund discovered several issues in enscript: it suffers from several buffer overflows (CAN-2004-1186), quotes and shell escape characters are insufficiently sanitized in filenames (CAN-2004-1185), and it supported taking input from an arbitrary command pipe, with unwanted side effects (CAN-2004-1184).
An attacker could design malicious files or input data which, once feeded into enscript, would trigger the execution of arbitrary code with the rights of the user running enscript.
There is no known workaround at this time.
All enscript users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=app-text/enscript-1.6.3-r3"