CVE-2020-28441 in conf-cfg-ini
Summary
by MITRE • 07/25/2022
This affects the package conf-cfg-ini before 1.2.2. If an attacker submits a malicious INI file to an application that parses it with decode, they will pollute the prototype on the application. This can be exploited further depending on the context.
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Analysis
by VulDB Data Team • 08/27/2022
The vulnerability identified as CVE-2020-28441 affects the conf-cfg-ini package version prior to 1.2.2, representing a critical prototype pollution issue that can be exploited through malicious INI file manipulation. This flaw resides in the decode function of the configuration parsing library, where an attacker can craft specially formatted INI files that manipulate the prototype chain of the application's object model. The vulnerability stems from insufficient input validation and sanitization during the parsing process, allowing malicious data to be injected into the prototype object which can then be leveraged by subsequent operations that rely on the application's object structure.
The technical exploitation of this vulnerability occurs when an application processes user-supplied INI configuration files through the vulnerable decode function. When the parser encounters specially crafted entries in the INI file, it can modify the prototype properties of objects within the application's memory space. This prototype pollution can lead to various security consequences including denial of service, privilege escalation, or remote code execution depending on how the application utilizes the parsed configuration data. The flaw specifically relates to CWE-471, which describes the insertion of data into the prototype of an object, making it a direct instance of prototype pollution vulnerabilities that have been increasingly targeted in recent years.
The operational impact of this vulnerability extends beyond simple configuration parsing, as prototype pollution can enable attackers to manipulate the behavior of applications in unexpected ways. When an application relies on object properties or methods that are inherited through the prototype chain, an attacker can potentially modify these inherited properties to alter application logic or bypass security controls. The vulnerability can be particularly dangerous in applications that perform dynamic object creation or that use features like JSON parsing, object cloning, or property enumeration that depend on the prototype chain structure. Depending on the application context, this could lead to authentication bypasses, data manipulation, or complete system compromise.
Mitigation strategies for CVE-2020-28441 require immediate patching of the conf-cfg-ini package to version 1.2.2 or later, which contains the necessary fixes to prevent prototype pollution during INI file parsing. Organizations should also implement input validation measures that sanitize configuration files before processing, particularly when dealing with user-supplied data. Additional defensive measures include implementing Content Security Policy headers, using secure parsing functions that do not allow prototype modification, and conducting regular security audits of third-party dependencies. The vulnerability aligns with ATT&CK technique T1059.007 for script injection and T1566 for social engineering, as it can be exploited through malicious configuration files delivered via various attack vectors including phishing or supply chain compromises. Security teams should monitor for any exploitation attempts through network traffic analysis and application logs that might indicate prototype pollution attacks, particularly when processing configuration files from untrusted sources.