SQL injection vulnerability in phpBB 2 before 2.0.18 allows remote attackers to execute arbitrary SQL commands via the topic type.
usercpregister.php in phpBB 2.0.17 allows remote attackers to modify regular expressions and execute PHP code via the signaturebbcodeuid parameter, as demonstrated by injecting an "e" modifier into a pregreplace statement.
phpBB 2.0.17 and earlier allows remote attackers to bypass protection mechanisms that deregister global variables by setting both a GET/POST/COOKIE (GPC) variable and a GLOBALS[] variable with the same name, which causes phpBB to unset the GLOBALS[] variable but not the GPC variable.
phpBB 2.0.17 and earlier, when registerglobals is enabled and the sessionstart function has not been called to handle a session, allows remote attackers to bypass security checks by setting the $SESSION and $HTTPSESSIONVARS variables to strings instead of arrays, which causes an arraymerge function call to fail.
SQL injection vulnerability in usercpregister.php in phpBB 2.0.17 allows remote attackers to execute arbitrary SQL commands via the signaturebbcodeuid parameter, which is not properly initialized.
phpBB 2.0.17 and earlier, when the registerlongarrays directive is disabled, allows remote attackers to modify global variables and bypass security mechanisms because PHP does not define the associated HTTP variables.
PHP remote file inclusion vulnerability in admin/admintopicactionlogging.php in Admin Topic Action Logging Mod 0.95 and earlier, as used in phpBB 2.0 up to 2.0.21, allows remote attackers to execute arbitrary PHP code via a URL in the phpbbrootpath parameter.
DISPUTED PHP remote file inclusion vulnerability in template.php in phpBB 2 allows remote attackers to execute arbitrary PHP code via a URL in the page parameter. NOTE: followup posts have disputed this issue, stating that template.php does not appear in phpBB and does not use a $page variable. It is possible that this is a site-specific vulnerability, or an issue in a mod.
The genrandstring function in phpBB 2.0.19 uses insufficiently random data (small value space) to create the activation key ("validation ID") that is sent by e-mail when establishing a password, which makes it easier for remote attackers to obtain the key and modify passwords for existing accounts or create new accounts.
Cross-site scripting (XSS) vulnerability in the private message box implementation (privmsg.php) in phpBB 2.0.x allows remote authenticated users to inject arbitrary web script or HTML via the "Message body" field in a message to a non-existent user.
A "missing request validation" error in phpBB 2 before 2.0.18 allows remote attackers to edit private messages of other users, probably by modifying certain parameters or other inputs.
phpBB 2.0.19 and earlier allows remote attackers to cause a denial of service (application crash) by (1) registering many users through profile.php or (2) using search.php to search in a certain way that confuses the database.
Cross-site request forgery (CSRF) vulnerability in phpBB 2.0.19, when Link to off-site Avatar or bbcode (IMG) are enabled, allows remote attackers to perform unauthorized actions as a logged in user via a link or IMG tag in a user profile, as demonstrated using links to (1) admin/adminusers.php and (2) modcp.php.
Cross-site scripting (XSS) vulnerability in phpBB 2.0.16 allows remote attackers to inject arbitrary web script or HTML via nested [url] tags.
Multiple cross-site scripting (XSS) vulnerabilities in phpBB 2.0.17 and earlier allow remote attackers to inject arbitrary web script or HTML via the (1) errormsg parameter to usercpregister.php, (2) forwardpage parameter to login.php, and (3) listcat parameter to search.php, which are not initialized as variables.
Cross-site scripting (XSS) vulnerability in adminsmilies.php in phpBB 2.0.19 allows remote attackers to inject arbitrary web script or HTML via Javascript events such as "onmouseover" in the (1) smileurl or (2) smileemotion parameters, which bypasses a check for "<" and ">" characters.