Eval injection vulnerability in lib/TWiki/Plugins.pm in TWiki before 6.0.1 allows remote attackers to execute arbitrary Perl code via the debugenableplugins parameter to do/view/Main/WebHome.
TWiki before 5.1.4 allows remote attackers to execute arbitrary shell commands by sending a crafted '%MAKETEXT{}%' parameter value containing Perl backtick characters.
lib/TWiki/Sandbox.pm in TWiki 6.0.0 and earlier, when running on Windows, allows remote attackers to bypass intended access restrictions and upload files with restricted names via a null byte (%00) in a filename to bin/upload.cgi, as demonstrated using .htaccess to execute arbitrary code.