The remote host is missing an update as announced via advisory SSA:2005-121-01.
New infozip (zip/unzip) packages are available for Slackware 8.1, 9.0, 9.1, 10.0, 10.1, and -current to fix security issues. - From the www.info-zip.org site: Zip 2.3 and (presumably) all previous versions have a buffer- overrun vulnerability relating to deep directory paths that could potentially lead to local privilege escalation (e.g., in the case of automated, Zip-based backups). See the FAQ page for details. All versions of UnZip through 5.50 have a number of directory- traversal vulnerabilities, and version 5.50 also has a textmode data- corruption bug that affects 16-bit ports such as MS-DOS. See the FAQ page for details.