CVE-2018-3749 in Deap
Summary
by MITRE
The utilities function in all versions < 1.0.1 of the deap node module can be tricked into modifying the prototype of Object when the attacker can control part of the structure passed to this function. This can let an attacker add or modify existing properties that will exist on all objects.
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Analysis
by VulDB Data Team • 02/24/2020
The vulnerability identified as CVE-2018-3749 resides within the deap node module, a popular library used for deep cloning and manipulation of JavaScript objects. This issue affects all versions prior to 1.0.1 and represents a critical prototype pollution vulnerability that can be exploited by malicious actors to manipulate the fundamental object structure of JavaScript applications. The vulnerability specifically targets the utilities function within the module, which processes user-controllable data structures and fails to properly sanitize input before incorporating it into the object prototype chain.
The technical flaw manifests when an attacker can influence the structure passed to the utilities function, allowing them to inject properties that become part of the Object prototype itself. This occurs due to inadequate input validation and sanitization within the module's implementation, creating a scenario where attacker-controlled data can be directly merged into the prototype object. The vulnerability is classified under CWE-471 as "Modification of Externally-Controlled Reference Data Structure" and represents a direct exploitation of prototype pollution mechanisms that have become increasingly common in modern web applications. When the utilities function processes attacker-controlled input, it fails to distinguish between legitimate object properties and prototype-polluting data, leading to the contamination of the global Object prototype.
The operational impact of this vulnerability is severe and far-reaching, as prototype pollution can enable a variety of attack vectors including but not limited to remote code execution, denial of service, and privilege escalation. Once an attacker successfully pollutes the Object prototype, any subsequent object creation or property access can be manipulated to execute malicious code or alter application behavior. The vulnerability can be leveraged to bypass security controls, manipulate application logic, and potentially gain unauthorized access to sensitive data or system resources. This type of vulnerability is particularly dangerous because it affects the core JavaScript object model and can have cascading effects throughout the entire application stack. The ATT&CK framework categorizes this under T1059.007 for "Command and Scripting Interpreter: JavaScript' and T1211 for 'Exploitation for Defense Evasion', as it enables attackers to manipulate application behavior at the most fundamental level.
Mitigation strategies for CVE-2018-3749 require immediate action to upgrade to version 1.0.1 or later of the deap node module where the prototype pollution vulnerability has been addressed. Organizations should implement comprehensive input validation and sanitization measures to prevent attacker-controlled data from reaching the utilities function, particularly in scenarios where user input is processed through object manipulation functions. Additionally, developers should consider implementing prototype pollution detection mechanisms, such as checking for polluted properties in the Object prototype before processing user data. The use of secure coding practices including the validation of object keys and properties, along with regular security audits of third-party dependencies, can significantly reduce the risk of exploitation. Organizations should also monitor their dependency trees for similar vulnerabilities and implement automated vulnerability scanning to detect and remediate such issues before they can be exploited in production environments.