The vulnerability in YesWiki before version 4.6.7 is a CSRF issue in the filemanager page handler. It improperly processes GET requests containing parameters such as do=del, erase, or emptytrash without validating a CSRF token. This allows an attacker to coerce an authenticated user into performing unwanted actions that delete or permanently purge page attachments. The CVSS 3.1 base score is 5.4, reflecting a medium severity with network attack vector, low attack complexity, no privileges required, but user interaction needed, and impacts on integrity and availability.

Successful exploitation results in unauthorized deletion or permanent purging of page attachments belonging to the targeted page owner or administrator. This can lead to loss of important data stored as attachments within YesWiki pages. There is no confidentiality impact reported. The attack requires user interaction (the victim must navigate to a malicious link) but no elevated privileges are needed beyond being logged in.

A fix is available in YesWiki version 4.6.7 and later. Users should upgrade to version 4.6.7 or newer to remediate this CSRF vulnerability. Until patched, users should avoid clicking untrusted links while logged in to YesWiki to reduce risk.