mghack has discovered multiple vulnerabilities in e107, which can be exploited by malicious users to conduct script insertion and SQL injection attacks and by malicious people to conduct cross-site scripting attacks.
1) Input passed via the URL to e107_images/thumb.php or rate.php is not properly sanitised before being returned to the user. This can be exploited to execute arbitrary HTML and script code in a user's browser session in context of an affected site.
2) Input passed to the "resend_name" POST parameter in e107_admin/users.php is not properly sanitised before being returned to the user. This can be exploited to execute arbitrary HTML and script code in a user's browser session in context of an affected site.
3) Certain input passed to the "link" BBCode in user signatures is not properly sanitised before being used. This can be exploited to insert HTML and script code, which will be executed in a user's browser session in context of an affected site if malicious data is viewed.
4) Input passed to the "username" POST parameter in usersettings.php is not properly sanitised before being used in a SQL query. This can be exploited to manipulate SQL queries by injecting arbitrary SQL code.
Successful exploitation of this vulnerability requires that the setting "Display name and login name may be different for" is set to e.g. "everyone (public)" (not default) and that "magic_quotes_gpc" is disabled.
The vulnerabilities are confirmed in version 0.7.26. Other versions may also be affected.