CVE-2016-10773 in cPanel
Summary
by MITRE
cPanel before 60.0.25 allows format-string injection in exception-message handling (SEC-171).
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Analysis
by VulDB Data Team • 07/20/2020
The vulnerability identified as CVE-2016-10773 represents a critical format-string injection flaw within the cPanel web hosting control panel software. This vulnerability specifically affects versions prior to 60.0.25 and occurs during exception-message handling processes. The issue stems from improper input validation and sanitization of user-supplied data when constructing error messages, creating an avenue for attackers to manipulate the format string used in message generation. Such vulnerabilities fall under the category of CWE-134 which specifically addresses the use of format strings with user-controlled data without proper validation or sanitization.
The technical exploitation of this vulnerability occurs when cPanel encounters an exception or error condition and attempts to display an error message to the user or system administrator. During this process, the software fails to properly escape or validate user input that may be included in the exception message, allowing an attacker to inject format specifiers such as %s, %d, or %x into the message template. When the application processes these malicious format specifiers, it can lead to information disclosure, denial of service, or potentially arbitrary code execution depending on the specific implementation details and system configuration. This type of vulnerability aligns with ATT&CK technique T1059.007 which covers the use of scripting languages for code execution and manipulation of system processes.
The operational impact of this vulnerability extends beyond simple information disclosure, as it can compromise the integrity and availability of the hosting environment. Attackers who successfully exploit this vulnerability can potentially extract sensitive memory contents, cause application crashes, or gain insights into the underlying system architecture that could facilitate further attacks. In a hosting environment, this could lead to unauthorized access to multiple customer accounts, data breaches, or complete service disruption. The vulnerability is particularly concerning because cPanel serves as a central management interface for web hosting services, making it a prime target for attackers seeking to compromise hosting infrastructure.
Mitigation strategies for CVE-2016-10773 primarily focus on immediate patching and implementation of proper input validation measures. Organizations should upgrade to cPanel version 60.0.25 or later, which includes fixes for the format-string injection vulnerability. Additionally, implementing proper input sanitization and validation procedures for all user-supplied data that may be used in message formatting is essential. Security controls should include regular vulnerability assessments, monitoring for unusual error message patterns, and implementing web application firewalls to detect and block potential exploitation attempts. The fix typically involves ensuring that all user input is properly escaped or sanitized before being incorporated into format strings, preventing malicious format specifiers from being processed. This vulnerability demonstrates the critical importance of proper error handling and input validation in security-critical applications, particularly those handling sensitive user data in hosting environments.