Multiple cross-site scripting (XSS) vulnerabilities in lib/TWiki.pm in TWiki before 5.0.1 allow remote attackers to inject arbitrary web script or HTML via (1) the rev parameter to the view script or (2) the query string to the login script.

Cross-site scripting (XSS) vulnerability in TWiki before 4.2.4 allows remote attackers to inject arbitrary web script or HTML via the %URLPARAM{}% variable.

TWiki 01-Dec-2000 up to 4.0.3 allows remote attackers to bypass the upload filter and execute arbitrary code via filenames with double extensions such as ".php.en", ".php.1", and other allowed extensions that are not .txt. NOTE: this is only a vulnerability when the server allows script execution in the pub directory.

TWiki 4.0, 4.0.1, and 20010901 through 20040904 allows remote authenticated users with edit rights to cause a denial of service (infinite recursion leading to CPU and memory consumption) via INCLUDE by URL statements that form a loop, such as a page that includes itself.