CVE-2023-26121 in safe-eval
Summary
by MITRE • 04/11/2023
All versions of the package safe-eval are vulnerable to Prototype Pollution via the safeEval function, due to improper sanitization of its parameter content.
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Analysis
by VulDB Data Team • 04/26/2023
The vulnerability identified as CVE-2023-26121 affects the safe-eval npm package, which is widely used for executing JavaScript code in a sandboxed environment. This package serves as a security layer that aims to prevent arbitrary code execution by sanitizing input before evaluation. However, the implementation contains a critical flaw that allows attackers to manipulate the prototype chain of JavaScript objects through the safeEval function. The vulnerability stems from insufficient validation and sanitization of parameter content passed to the evaluation function, creating a pathway for prototype pollution attacks that can compromise the security of applications relying on this package.
The technical flaw manifests when malicious input is passed to the safeEval function, enabling attackers to inject code that modifies the Object.prototype or other core JavaScript objects. This occurs because the package fails to properly sanitize or validate the content of parameters before processing them, allowing attackers to manipulate the prototype chain of objects. The vulnerability is particularly dangerous because it can be exploited to modify the behavior of core JavaScript functions and objects, potentially leading to arbitrary code execution or bypassing security controls. The prototype pollution attack vector allows attackers to inject malicious properties into the prototype, which then get inherited by all objects created from that prototype, effectively enabling persistent modifications to the runtime environment.
The operational impact of this vulnerability is significant for organizations using the safe-eval package, as it can lead to complete system compromise when exploited. Applications that rely on this package for evaluating user input or dynamic code execution become vulnerable to attacks that can result in data breaches, privilege escalation, or complete system takeover. The vulnerability affects all versions of the package, meaning that even the latest releases may be susceptible if they haven't been patched. Attackers can leverage this flaw to inject malicious code that executes with the privileges of the running application, potentially accessing sensitive data, modifying system behavior, or establishing persistent backdoors. This type of vulnerability is particularly concerning in environments where the package is used to evaluate untrusted input from users or external sources.
Mitigation strategies for CVE-2023-26121 should prioritize immediate patching of the vulnerable package to the latest secure version that addresses the prototype pollution issue. Organizations should conduct comprehensive vulnerability assessments to identify all applications and systems using the affected package and ensure proper input validation is implemented at multiple layers. The remediation process should include updating the package dependencies, implementing additional input sanitization measures, and monitoring for potential exploitation attempts. Security teams should also consider implementing runtime protection mechanisms and network segmentation to limit the potential impact of successful attacks. The vulnerability aligns with CWE-471, which describes the improper handling of prototype pollution, and can be mapped to ATT&CK technique T1059.007 for JavaScript execution, emphasizing the need for robust input validation and secure coding practices in JavaScript environments.