Cross-Site Request Forgery (CSRF)
The message_options function in includes/ucp/ucp_pm_options.php in phpBB 3.1 before 3.1.0-RC4 and 3.0 before 3.0.13 does not properly validate the form key, which allows remote attackers to conduct CSRF attacks and change the full folder setting via unspecified vectors.
CWE-352 - Cross-Site Request Forgery (CSRF)
Cross-Site Request Forgery (CSRF) is a vulnerability that allows an attacker to make arbitrary requests in an authenticated vulnerable web application and disrupt the integrity of the victim’s session. The impact of a successful CSRF attack may range from minor to severe, depending upon the capabilities exposed by the vulnerable application and privileges of the user. An attacker may force the user to perform state-changing requests like transferring funds, changing their email address or password etc. However, if an administrative level account is affected, it may compromise the whole web application and associated sensitive data.