phpBB OAuth Authentication and SQL Injection Flaws

Account hijacking in phpBB is possible due to improper authentication checks in the OAuth implementation, affecting default installations even when OAuth is not configured or enabled. Remote unauthenticated attackers can gain unauthorized access to arbitrary accounts on the forum platform, with no public exploit identified at time of analysis despite the critical 9.8 CVSS score.

Account takeover in phpBB via OAuth state-verification flaw enables remote attackers to link a victim's forum account to an attacker-controlled identity provider account. Successful exploitation requires the victim to click an attacker-crafted link while authenticated, after which the attacker can authenticate as the victim through the linked external provider. No public exploit identified at time of analysis, but a vendor community advisory has been published.

SQL injection in phpBB forum software allows authenticated users to execute arbitrary SQL queries through a flawed profile field migration routine. Only forums that were upgraded from a pre-3.3.8 release and have not yet reached 3.3.11 are affected, narrowing the exposed population to a specific upgrade window. No public exploit identified at time of analysis, and EPSS data was not provided.