The csrf_callback function in the CSRF Magic library through 2016-03-27 is vulnerable to CSRF protection bypass as it allows one to tamper with the csrf token values. A remote attacker can exploit this by crafting a malicious page and dispersing it to a victim via social engineering, enticing them to click the link. Once the user/victim clicks the "try again" button, the attacker can take over the account and perform unintended actions on the victim's behalf. NOTE: A third-party maintainer has stated that this CVE is a false report. They state that the csrf_callback function is actually a callback function to the callers own handler for output. The function called can be changed via configuration to a custom callback to handle failed validation differently. They also stated that there is no way for an attacker to change tokens to make them valid from the client side. The only thing an attack can do is to pull the token out of the javascript, but that will always be possible and has nothing to do with the callback