Cross-site scripting (XSS) vulnerability in index.html in IceWarp WebMail 5.5.1 and earlier allows remote attackers to inject arbitrary web script or HTML via the PHPSESSID parameter.

Multiple TCP implementations with Protection Against Wrapped Sequence Numbers (PAWS) with the timestamps option enabled allow remote attackers to cause a denial of service (connection loss) via a spoofed packet with a large timer value, which causes the host to discard later packets because they appear to be too old.

MERAK Mail Server 7.6.0 with Icewarp Web Mail 5.3.0 allows remote authenticated users to gain sensitive information via an HTTP request to (1) calendar_d.html, (2) calendar_m.html, (3) calendar_w.html, or (4) calendar_y.html, which reveal the installation path.

MERAK Mail Server 7.6.0 with Icewarp Web Mail 5.3.0 and Mail Server 7.6.4r with Icewarp Mail Server 5.3.2 uses weak encryption in the (1) users.cfg, (2) settings.cfg, (3) users.dat or (4) user.dat files, which allows local users to extract the passwords.

Multiple cross-site scripting vulnerabilities in MERAK Mail Server 7.6.0 with Icewarp Web Mail 5.3.0 allow remote attackers to inject arbitrary web script or HTML via the (1) username parameter to login.html, (2) accountid parameter to accountsettings_add.html, or the (3) note, (4) title, and (5) location fields to calendar.html.