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) error_msg parameter to usercp_register.php, (2) forward_page parameter to login.php, and (3) list_cat parameter to search.php, which are not initialized as variables.
SQL injection vulnerability in usercp_register.php in phpBB 2.0.17 allows remote attackers to execute arbitrary SQL commands via the signature_bbcode_uid parameter, which is not properly initialized.
usercp_register.php in phpBB 2.0.17 allows remote attackers to modify regular expressions and execute PHP code via the signature_bbcode_uid parameter, as demonstrated by injecting an "e" modifier into a preg_replace statement.
Interpretation conflict in phpBB 2.0.17, with remote avatars and avatar uploading enabled, allows remote authenticated users to inject arbitrary web script or HTML via an HTML file with a GIF or JPEG file extension, which causes the HTML to be executed by a victim who views the file in Internet Explorer, which renders malformed image types as HTML, enabling cross-site scripting (XSS) attacks. NOTE: it could be argued that this vulnerability is due to a design flaw in Internet Explorer (CVE-2005-3312) and the proper fix should be in that browser; if so, then this should not be treated as a vulnerability in phpBB.
The bbencode_second_pass and make_clickable functions in bbcode.php for phpBB before 2.0.15, as used in viewtopic.php, privmsg.php, and other scripts, allow remote attackers to execute arbitrary script via a BBcode tag with a (1) javascript:, (2) applet:, (3) about:, (4) activex:, (5) chrome:, or (6) script: URI scheme, as demonstrated using the URL tag.
phpBB 2.0.13 and earlier allows remote attackers to obtain sensitive information via a direct request to oracle.php, which reveals the path in a PHP error message.
Cross-site scripting (XSS) vulnerability in usercp_register.php for phpBB 2.0.13 allows remote attackers to inject arbitrary web script or HTML by setting the (1) allowhtml, (2) allowbbcode, or (3) allowsmilies parameters to inject HTML into signatures for personal messages, possibly when they are processed by privmsg.php or viewtopic.php.