YesWiki versions 1 and 2 suffers from remote arbitrary file upload and directory traversal vulnerabilities.
You can download this exploit from the following link: https://packetstormsecurity.com/files/download/134690/yeswiki-shelltraversal.txt
Source: https://packetstormsecurity.com/files/134690/YesWiki-1-2-File-Upload-Directory-Traversal.html