CVE-2021-3797 in hestiacp
Summary
by MITRE • 09/15/2021
hestiacp is vulnerable to Use of Wrong Operator in String Comparison
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Analysis
by VulDB Data Team • 09/17/2021
The vulnerability identified as CVE-2021-3797 affects the Hestia Control Panel, a web-based server management interface used for hosting environments. This critical security flaw resides in the application's handling of string comparison operations where an incorrect operator is being utilized, potentially allowing malicious actors to bypass authentication mechanisms or manipulate system behavior through crafted input. The issue stems from improper validation of user-supplied data during authentication or access control checks, creating a pathway for unauthorized access to protected system resources.
The technical root cause of this vulnerability manifests as a use of wrong operator in string comparison, which aligns with CWE-707, a weakness category that encompasses improper use of operations. In the context of HestiaCP, this flaw likely occurs when the application employs a non-strict comparison operator such as == instead of === in php or similar scripting environments, allowing attackers to exploit type coercion behaviors. When comparing strings with numeric values or malformed input, the incorrect operator can cause the comparison to evaluate as true even when the strings are not genuinely equal, leading to unexpected program flow and potential privilege escalation.
The operational impact of this vulnerability extends beyond simple authentication bypasses, as it can enable attackers to manipulate various system functions that rely on string comparisons for access control decisions. An attacker exploiting this flaw could potentially gain unauthorized access to administrative panels, modify user accounts, access restricted files, or perform other malicious activities within the compromised environment. The vulnerability's severity is amplified by the fact that it affects a control panel used for managing critical server infrastructure, making it a prime target for attackers seeking persistent access to hosting environments.
Mitigation strategies for CVE-2021-3797 should prioritize immediate patching of affected HestiaCP installations, with administrators verifying that all systems have been updated to versions that address the specific string comparison implementation. Security teams should also implement network-based monitoring to detect unusual authentication patterns or attempts to exploit the vulnerability, while conducting thorough access reviews to identify any potential compromise. Organizations should enforce strict input validation policies and ensure that all string comparisons within the application use appropriate strict comparison operators to prevent similar issues from occurring in other components of the system. The vulnerability demonstrates the importance of adhering to secure coding practices and following the principle of least privilege in web application development, as outlined in the mitre attack framework's defense-in-depth approach to mitigating common software weaknesses.