CVE-2021-36380

Sunhillo SureLine before 9.1.5 contains an authentication bypass vulnerability that allows an unauthenticated remote attacker to impersonate any user with an active web session by forging a session cookie containing only a cleartext username with no random identifier or integrity protection. Attackers can guess default account names such as Admin or sftp_user and submit a forged username cookie to satisfy the login check in checkLogin (libwebcmn.so) and networkDiag.cgi, chaining into root command execution.

Sunhillo SureLine before 9.1.5 contains an OS command injection vulnerability in the networkDiag.cgi endpoint that allows an authenticated remote attacker with any web account to execute arbitrary commands as root by injecting shell metacharacters into the ipAddr or dnsAddr parameters. Attackers can bypass the incomplete character denylist from the prior CVE-2021-36380 fix using URL-encoded newline (%0a) or ampersand (%26) sequences that act as command separators after decoding in the ping, nslookup, or traceroute diagnostic modes, leading to full system compromise.

Sunhillo SureLine before 9.1.5 contains a path traversal vulnerability in the radarUpdater.cgi endpoint that allows unauthenticated remote attackers to read arbitrary files with root privileges due to missing authentication checks and insufficient sanitization of the filename parameter. Attackers can use directory traversal sequences to access sensitive files such as /etc/shadow, the web user database, the root SSH private key, and the device's TLS private key, leading to full system compromise.