CVE-2018-5235 in Utilities
Summary
by MITRE
Norton Utilities (prior to 16.0.3.44) may be susceptible to a DLL Preloading vulnerability, which is a type of issue that can occur when an application looks to call a DLL for execution and an attacker provides a malicious DLL to use instead. Depending on how the application is configured, it will generally follow a specific search path to locate the DLL. The vulnerability can be exploited by a simple file write (or potentially an over-write) which results in a foreign DLL running under the context of the application.
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Analysis
by VulDB Data Team • 03/17/2020
The vulnerability identified as CVE-2018-5235 affects Norton Utilities versions prior to 16.0.3.44 and represents a critical DLL preloading weakness that exploits the application's dynamic link library loading mechanism. This flaw falls under the category of CWE-426 Untrusted Search Path, where applications fail to properly validate the source of dynamically loaded libraries. The vulnerability stems from the application's insecure search path implementation, which allows attackers to place malicious DLL files in directories that the application searches before checking the system's legitimate library locations. When Norton Utilities attempts to load a required DLL, it follows a predictable search order that includes the current working directory, potentially enabling an attacker to execute arbitrary code with the privileges of the running application. This type of vulnerability is particularly dangerous because it can be exploited through simple file operations such as write or overwrite actions, making it accessible to attackers with minimal technical expertise.
The operational impact of this vulnerability extends beyond simple code execution, as it can enable attackers to escalate privileges and perform malicious activities within the context of the Norton Utilities application. The attack vector typically involves placing a specially crafted malicious DLL in the same directory as the vulnerable application or in a location that the application's search path will prioritize over legitimate system libraries. When Norton Utilities executes and attempts to load a dependent DLL, the system will first locate and execute the attacker-controlled malicious DLL instead of the legitimate one. This behavior aligns with the ATT&CK framework's technique T1059 Command and Scripting Interpreter, where adversaries leverage legitimate system tools and processes to execute malicious code. The vulnerability can be exploited in various scenarios including local privilege escalation, persistent backdoor installation, and data exfiltration, as the malicious DLL runs with the same privileges as the Norton Utilities process, which often includes elevated permissions due to the nature of system utility applications.
Mitigation strategies for CVE-2018-5235 require both immediate patching and defensive configuration measures to address the underlying DLL preloading vulnerability. Organizations should immediately update to Norton Utilities version 16.0.3.44 or later, which contains the necessary fixes to prevent insecure DLL loading behaviors. Additionally, system administrators should implement proper directory permissions and access controls to prevent unauthorized file creation in directories where Norton Utilities executes. The principle of least privilege should be enforced by running Norton Utilities with minimal required permissions rather than elevated privileges. Security configurations should include enabling Windows Defender Application Control or similar application whitelisting solutions to restrict which DLLs can be loaded by the application. From a defensive perspective, monitoring for suspicious file creation patterns in application directories and implementing file integrity monitoring can help detect potential exploitation attempts. Network-based detection measures should also be deployed to monitor for unusual network connections initiated by Norton Utilities, as malicious DLLs may attempt to communicate with command and control servers. The vulnerability demonstrates the importance of secure coding practices and proper DLL loading mechanisms, emphasizing the need for developers to implement secure search path handling and avoid relying on insecure default loading behaviors that can be easily exploited by attackers.