This indicates an attack attempt to exploit an Information Disclosure Vulnerability in SonicWALL SSL-VPN.
The vulnerability is due to an error in the vulnerable application when handling a maliciously crafted HTTPS request. An attacker can exploit this to access sensitive information on the affected machine via a crafted HTTPS request.
SonicWALL SSL-VPN 4000 3.5 4
SonicWALL SSL-VPN 2000 3.5 4
SonicWALL SSL-VPN 200 3.0 8
SonicWALL SSL VPN 200 2.1
Information Disclosure: Remote attackers can gain sensitive information from vulnerable systems.
Applied latest patch or update from the vendor.