CVE-2016-10807 in cPanel
Summary
by MITRE
cPanel before 57.9999.54 allows certain denial-of-service outcomes via /scripts/killpvhost (SEC-112).
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Analysis
by VulDB Data Team • 07/22/2020
The vulnerability identified as CVE-2016-10807 affects cPanel versions prior to 57.9999.54 and represents a significant denial-of-service weakness within the web hosting control panel ecosystem. This flaw specifically resides in the /scripts/killpvhost component which is designed to handle process cleanup operations for virtual hosts within the cPanel environment. The vulnerability stems from insufficient input validation and improper handling of user-supplied parameters that are processed by this critical script. Attackers can exploit this weakness by crafting malicious requests that manipulate the script's behavior, leading to system resource exhaustion or process termination that ultimately disrupts legitimate service operations for hosting customers.
The technical implementation of this vulnerability involves the manipulation of parameters passed to the killpvhost script which is responsible for terminating processes associated with specific virtual hosts. When cPanel processes these requests without adequate sanitization, it creates opportunities for attackers to cause the system to consume excessive resources or enter unstable states. This occurs because the script fails to properly validate the scope and boundaries of input parameters, allowing attackers to potentially trigger cascading failures in the hosting environment. The flaw essentially enables an attacker to cause the system to perform unintended operations that exhaust available resources or disrupt normal process management functions.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise the stability and reliability of entire hosting environments. When exploited, the denial-of-service condition can affect multiple virtual hosts simultaneously, causing widespread service degradation for customers hosted on the same server. This vulnerability particularly impacts shared hosting environments where multiple customers operate under the same control panel infrastructure, as a single malicious actor can potentially disrupt services for numerous users. The consequences include extended downtime, loss of customer confidence, and potential revenue loss for hosting providers who rely on consistent service availability.
Organizations should implement immediate mitigations including upgrading to cPanel version 57.9999.54 or later which contains the necessary patches to address this vulnerability. System administrators should also consider implementing additional monitoring and access controls around the /scripts/killpvhost endpoint to detect and prevent unauthorized exploitation attempts. Network-level protections such as rate limiting and input validation firewalls can provide additional layers of defense. The vulnerability aligns with CWE-20, which describes improper input validation, and maps to ATT&CK technique T1499.004 for network denial of service. Regular security assessments and vulnerability scanning should be conducted to identify similar weaknesses in other components of the hosting infrastructure, as this represents a pattern of inadequate input validation that could exist elsewhere in the system architecture.