b2evolution Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') Vulnerability (CVE-2017-5539)
Description
The patch for directory traversal (CVE-2017-5480) in b2evolution version 6.8.4-stable has a bypass vulnerability. An attacker can use ..\/ to bypass the filter rule. Then, this attacker can exploit this vulnerability to delete or read any files on the server. It can also be used to determine whether a file exists.