Updated unzip packages resolving a vulnerability allowing arbitrary files to be overwritten are now available. [Updated 15 August 2003] Ben Laurie found that the original patch to fix this issue missed a case where the path component included a quoted slash. These updated packages contain a new patch that corrects this issue.
The unzip utility is used for manipulating archives, which are multiple files stored inside of a single file. A vulnerabilitiy in unzip version 5.50 and earlier allows attackers to overwrite arbitrary files during archive extraction by placing invalid (non-printable) characters between two "." characters. These non-printable characters are filtered, resulting in a ".." sequence. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CAN-2003-0282 to this issue. This erratum includes a patch ensuring that non-printable characters do not make it possible for a malicious .zip file to write to parent directories unless the "-:" command line parameter is specified. Users of unzip are advised to upgrade to these updated packages, which are not vulnerable to this issue.