CVE-2020-7672 in mosc
Summary
by MITRE
mosc through 1.0.0 is vulnerable to Arbitrary Code Execution. User input provided to `properties` argument is executed by the `eval` function, resulting in code execution.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 06/11/2020
The mosc library version 1.0.0 contains a critical vulnerability that exposes systems to arbitrary code execution through improper input handling within its properties argument processing. This vulnerability stems from the library's reliance on the eval function to execute user-provided input, creating a direct pathway for malicious actors to inject and execute arbitrary code on affected systems. The flaw exists in the library's design where untrusted input is directly passed to eval without proper sanitization or validation, making it susceptible to code injection attacks. The vulnerability specifically affects the properties argument handling mechanism, which processes user-supplied data and executes it as code, bypassing normal security controls and access restrictions that would typically prevent such execution.
This security weakness represents a classic example of unsafe dynamic code execution practices that fall under CWE-94, which describes "Improper Control of Generation of Code ('Code Injection')." The vulnerability allows attackers to craft malicious input that when processed by the eval function, executes unintended commands on the target system. The impact extends beyond simple code execution to potentially enable full system compromise, as the executed code operates with the privileges of the affected application. The flaw is particularly dangerous because it requires minimal attacker input to achieve significant system compromise, making it an attractive target for automated exploitation tools and malicious actors seeking to gain unauthorized access to systems running vulnerable versions of the library.
The operational impact of this vulnerability is severe and multifaceted, as it can lead to complete system compromise, data exfiltration, and persistence mechanisms being established by attackers. Systems utilizing mosc version 1.0.0 are at risk of having their applications hijacked, with attackers able to execute commands, access sensitive data, and potentially escalate privileges. The vulnerability can be exploited through various attack vectors including web applications, APIs, or any interface that accepts user input and processes it through the affected library. The use of eval for user input processing violates fundamental security principles and creates an attack surface that aligns with techniques documented in the ATT&CK framework under T1059.001 for Command and Scripting Interpreter, specifically targeting the execution of malicious code through interpreted languages. Organizations running vulnerable systems may experience unauthorized access, data breaches, and potential lateral movement within their network infrastructure.
Mitigation strategies should focus on immediate remediation through library version updates to address the core vulnerability, while also implementing input validation and sanitization measures to prevent similar issues in other components. Organizations should conduct comprehensive vulnerability assessments to identify all systems utilizing affected versions of mosc and ensure prompt patching. The recommended approach involves replacing the eval-based execution with safer alternatives such as JSON parsing or other controlled execution methods that do not permit arbitrary code execution. Security teams should also implement monitoring and detection mechanisms to identify potential exploitation attempts, including logging and alerting on unusual code execution patterns. Additionally, developers should adopt secure coding practices that avoid using eval with user-provided input, following the principle of least privilege and implementing proper input validation to prevent injection attacks. The vulnerability highlights the importance of avoiding dynamic code execution in security-sensitive applications and demonstrates the critical need for thorough code reviews and security testing to identify such dangerous patterns before they can be exploited in production environments.