HestiaCP versions 1.2.0 through 1.9.4 contain an IP spoofing vulnerability that allows unauthenticated remote attackers to bypass authentication security controls by supplying an arbitrary IP address in the CF-Connecting-IP HTTP header without verifying the request originated from Cloudflare's network. Attackers can exploit this to circumvent fail2ban brute-force protection, bypass per-user IP allowlists, and poison authentication audit logs by spoofing trusted IP addresses on each request.

HestiaCP before 1.9.5 contains an authenticated OS command injection vulnerability that allows low-privilege authenticated users to execute arbitrary commands as root by injecting a single-quote character into unvalidated DNS record types. Attackers can exploit insufficient input validation in isdnsrecordformatvalid() combined with unsafe eval-based parsing in updatedomainzone() to prematurely close a variable assignment string and achieve full root code execution on the underlying host in a single DNS record creation step.

HestiaCP before 1.9.5 contains a stored cross-site scripting vulnerability that allows authenticated low-privilege users to inject arbitrary HTML by creating a DNS record with a double-quote followed by a script payload in the value field. The application fails to apply htmlspecialchars() encoding to the DNS record value field rendered into the data-sort-value HTML attribute in listdnsrec.php, allowing the payload to execute in the browser of any user who views the DNS record list, including administrators.

HestiaCP versions 1.9.0 through 1.9.4 contain a deserialization vulnerability in the web terminal component caused by a session format mismatch between PHP and Node.js that allows unauthenticated remote attackers to achieve root-level code execution. Attackers can inject crafted data into HTTP headers that are processed by the PHP session handler but incorrectly deserialized by the Node.js web terminal component as trusted session values, resulting in arbitrary command execution on systems with the web terminal feature enabled.