An Improper Access Control vulnerability in Fortinet FortiWeb 5.6.0 up to but not including 6.1.0 under "Signed Security Mode", allows attacker to bypass the signed user cookie protection by removing the FortiWeb own protection session cookie.

A condition for session fixation vulnerability [CWE-384] in the session management of FortiWeb versions 6.4 all versions, 6.3.0 through 6.3.16, 6.2.0 through 6.2.6, 6.1.0 through 6.1.2, 6.0.0 through 6.0.7, 5.9.0 through 5.9.1 may allow a remote, unauthenticated attacker to infer the session identifier of other users and possibly usurp their session.

Multiple stack-based buffer overflow vulnerabilities [CWE-121] in the proxy daemon of FortiWeb 5.x all versions, 6.0.7 and below, 6.1.2 and below, 6.2.6 and below, 6.3.16 and below, 6.4 all versions may allow an unauthenticated remote attacker to achieve arbitrary code execution via specifically crafted HTTP requests.

A stack-based buffer overflow in Fortinet FortiWeb 6.4 all versions, FortiWeb versions 6.3.17 and earlier, FortiWeb versions 6.2.6 and earlier, FortiWeb versions 6.1.2 and earlier, FortiWeb versions 6.0.7 and earlier, FortiWeb versions 5.9.1 and earlier, FortiWeb 5.8 all versions, FortiWeb 5.7 all versions, FortiWeb 5.6 all versions allows attacker to execute unauthorized code or commands via specially crafted command arguments.