Clearswift MIMEsweeper for Web before 5.1.15 Hotfix allows remote attackers to cause a denial of service (crash) via an encrypted archived .RAR file, which triggers a scan error and causes the Web Policy Engine service to terminate.

Cross-site scripting (XSS) vulnerability in Clearswift MIMEsweeper for Web before 5.1.15 Hotfix allows remote attackers to inject arbitrary web script or HTML via the URL, which is reflected back in an error message when trying to access a blocked web site.

Clearswift MIMEsweeper For Web (a.k.a. WEBsweeper) 4.0 through 5.1 allows remote attackers to bypass filtering via a URL that does not include a .exe extension but returns an executable file.

Clearswift MIMEsweeper 5.0.5, when it has been upgraded from MAILsweeper for SMTP version 4.3 or MAILsweeper Business Suite I or II, allows remote attackers to bypass scanning by including encrypted data in a mail message, which causes the message to be marked as "Clean" instead of "Encrypted".

Directory traversal vulnerability in MIMEsweeper for Web before 5.0.4 allows remote attackers or local users to read arbitrary files via "..\\", "..\", and similar dot dot sequences in the URL.