CVE-2020-7675 in cd-messenger
Summary
by MITRE
cd-messenger through 2.7.26 is vulnerable to Arbitrary Code Execution. User input provided to the `color` argument executed by the `eval` function resulting in code execution.
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Analysis
by VulDB Data Team • 06/11/2020
The vulnerability identified as CVE-2020-7675 affects cd-messenger versions through 2.7.26 and represents a critical arbitrary code execution flaw that stems from improper input validation and unsafe code execution practices. This vulnerability specifically manifests when user-provided data is passed to the color argument of the application, which is then processed through the eval function. The use of eval in this context creates a direct pathway for malicious actors to inject and execute arbitrary code within the application's runtime environment, effectively bypassing normal security controls and access restrictions that would typically protect the system.
The technical implementation of this vulnerability demonstrates a classic unsafe evaluation pattern that falls under CWE-94, which specifically addresses the execution of arbitrary code through the use of eval or similar functions. When an application accepts user input and directly evaluates it as code without proper sanitization or validation, it creates a dangerous attack surface where adversaries can craft malicious payloads that execute with the privileges of the vulnerable application. The color argument serves as the attack vector because it likely represents a configuration parameter that allows users to customize visual elements, but the application fails to properly validate or sanitize this input before processing it through the eval mechanism.
Operationally, this vulnerability poses significant risks to systems running affected versions of cd-messenger as it enables remote code execution capabilities that can be exploited by attackers without requiring authentication or elevated privileges. The impact extends beyond simple code execution to potentially allow full system compromise, data exfiltration, and persistence mechanisms. Attackers can leverage this vulnerability to install backdoors, escalate privileges, or use the compromised system as a launch point for further attacks within the network infrastructure. The vulnerability is particularly concerning because it can be triggered through normal user interactions with the application's color configuration features, making it accessible to both authenticated and unauthenticated attackers depending on the application's deployment model.
The mitigation strategies for CVE-2020-7675 should focus on eliminating the use of eval functions with user-provided input and implementing proper input validation and sanitization mechanisms. Organizations should immediately upgrade to cd-messenger version 2.7.27 or later, which contains the necessary patches to address this vulnerability. Additionally, implementing proper parameter validation, using safe alternatives to eval such as JSON parsing or switch statements, and employing input sanitization techniques can prevent similar vulnerabilities from occurring in other parts of the application. Security monitoring should be enhanced to detect unusual patterns of color parameter usage that might indicate exploitation attempts. The vulnerability aligns with ATT&CK technique T1059.007, which covers the use of scripting languages for execution, and represents a clear example of how improper input handling can create persistent security risks that require immediate remediation.