phpBB before 3.3.16 is vulnerable to Host Header Injection that can lead to password rest link poisoning. When force_server_vars is disabled, the servers hostname may be extracted from the HTTP Host header which is used to generate the password reset link URL. An attacker who can manipulate the Host header (e.g. through misconfigured host setup or missing header validation by the webserver) can cause password reset emails to contain a link pointing to an attacker-controlled domain, potentially leading to account takeover.

Cross Site Request Forgery vulnerability in Phpbb phbb3 v.3.3.15 allows a local attacker to execute arbitrary code via the Admin Control Panel icon management functionality.

Cross Site Request Forgery vulnerability in Phpbb phbb3 v.3.3.15 allows a local attacker to execute arbitrary code via the login function and the authentication mechanism

A vulnerability, which was classified as problematic, has been found in phpBB up to 3.3.10. This issue affects the function main of the file phpBB/includes/acp/acp_icons.php of the component Smiley Pack Handler. The manipulation of the argument pak leads to cross site scripting. The attack may be initiated remotely. Upgrading to version 3.3.11 is able to address this issue. The patch is named ccf6e6c255d38692d72fcb613b113e6eaa240aac. It is recommended to upgrade the affected component. The associated identifier of this vulnerability is VDB-244307.

A vulnerability exists in phpBB <v3.2.10 and <v3.3.1 which allowed remote image dimensions check to be used to SSRF.

phpBB 3.2.7 allows adding an arbitrary Cascading Style Sheets (CSS) token sequence to a page through BBCode.

Missing form token validation in phpBB 3.2.7 allows CSRF in deleting post attachments.

phpBB 3.2.8 allows a CSRF attack that can approve pending group memberships.

phpBB 3.2.8 allows a CSRF attack that can modify a group avatar.

phpbb 3.0.x-3.0.6 has an XSS vulnerability via the [flash] BB tag.

In phpBB before 3.1.7-PL1, includes/acp/acp_bbcodes.php has improper verification of a CSRF token on the BBCode page in the Administration Control Panel. An actual CSRF attack is possible if an attacker also manages to retrieve the session id of a reauthenticated administrator prior to targeting them.

phpBB version 3.2.7 allows the stealing of an Administration Control Panel session id by leveraging CSRF in the Remote Avatar feature. The CSRF Token Hijacking leads to stored XSS

Server side request forgery (SSRF) in phpBB before 3.2.6 allows checking for the existence of files and services on the local network of the host through the remote avatar upload function.

The fulltext search component in phpBB before 3.2.6 allows Denial of Service.

Passing an absolute path to a file_exists check in phpBB before 3.2.4 allows Remote Code Execution through Object Injection by employing Phar deserialization when an attacker has access to the Admin Control Panel with founder permissions.

phpBB version 3.2.0 is vulnerable to SSRF in the Remote Avatar function resulting allowing an attacker to perform port scanning, requesting internal content and potentially attacking such internal services via the web application.

Open redirect vulnerability in phpBB before 3.0.14 and 3.1.x before 3.1.4 allows remote attackers to redirect users of Google Chrome to arbitrary web sites and conduct phishing attacks via unspecified vectors.

The message_options function in includes/ucp/ucp_pm_options.php in phpBB 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.

Cross-site scripting (XSS) vulnerability in includes/startup.php in phpBB before 3.0.13 allows remote attackers to inject arbitrary web script or HTML via vectors related to "Relative Path Overwrite."

Unspecified vulnerability in posting.php in phpBB before 3.0.5 has unknown impact and attack vectors related to the use of a "forum id" in circumstances related to a "global announcement."

feed.php in phpBB 3.0.7 before 3.0.7-PL1 does not properly check permissions for feeds, which allows remote attackers to bypass intended access restrictions via unspecified attack vectors related to permission settings on a private forum.

SQL injection vulnerability in root/includes/prime_quick_style.php in the Prime Quick Style addon before 1.2.3 for phpBB 3 allows remote authenticated users to execute arbitrary SQL commands via the prime_quick_style parameter to ucp.php.

phpBB 2.0.23 includes the session ID in a request to modcp.php when the moderator or administrator closes a thread, which allows remote attackers to hijack the session via a post in the thread containing a URL to a remotely hosted image, which might include the session ID in the Referer header.

Unspecified vulnerability in phpBB before 3.0.4 allows attackers to obtain sensitive information via unknown vectors related to the lack of password prompts for a private message that quotes a post in a password-protected forum.

Unspecified vulnerability in phpBB before 3.0.4 allows attackers to bypass intended access restrictions and activate de-activated accounts via unknown vectors.