CVE-2017-16113 in parsejson
Summary
by MITRE
The parsejson module is vulnerable to regular expression denial of service when untrusted user input is passed into it to be parsed.
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Analysis
by VulDB Data Team • 03/21/2023
The CVE-2017-16113 vulnerability resides within the parsejson module, a widely used JavaScript library for parsing JSON data structures. This particular weakness manifests as a regular expression denial of service attack vector that can be exploited when untrusted user input is processed through the module's parsing functions. The vulnerability stems from the module's use of inefficient regular expressions that can be manipulated to cause significant performance degradation or complete system unresponsiveness. When maliciously crafted input is passed to the parsejson parser, it triggers catastrophic backtracking in the regular expression engine, causing the application to consume excessive CPU resources and potentially leading to service interruption. The vulnerability affects applications that rely on this module for JSON parsing operations, particularly those that process user-supplied data without proper input validation or sanitization. Attackers can exploit this weakness by crafting specific input patterns that cause the regular expressions to enter exponential time complexity during matching operations, effectively creating a denial of service condition.
The technical implementation of this vulnerability aligns with CWE-400, which categorizes excessive resource consumption due to inefficient regular expressions. The parsejson module's parsing logic employs regular expressions that are susceptible to catastrophic backtracking when confronted with malicious input patterns. This occurs because the regular expression engine must explore numerous potential matches before determining that no valid match exists, leading to exponential execution time growth. The vulnerability operates at the application layer and can be classified under the ATT&CK technique T1499.1, which describes resource exhaustion attacks targeting application performance. The attack vector specifically targets the input processing pipeline where user data enters the application, making it particularly dangerous in web applications that handle user submissions. The module's parsing functions do not implement proper input validation or timeout mechanisms, allowing the malicious input to propagate through the system without adequate protection.
The operational impact of CVE-2017-16113 extends beyond simple service disruption to potentially compromise entire application availability and user experience. When exploited, the vulnerability can cause applications to become unresponsive or crash entirely, affecting multiple users simultaneously. Web applications utilizing the parsejson module become vulnerable to denial of service attacks that can be executed with relatively simple input patterns, making the exploit accessible to attackers with basic technical knowledge. The vulnerability is particularly concerning in high-traffic environments where a single malicious request can consume significant system resources and impact service availability for other legitimate users. Organizations running applications that depend on this module may experience cascading failures if the vulnerability is not addressed promptly, as the denial of service condition can propagate through the application stack. The impact is further amplified in cloud environments where resource consumption directly affects billing and performance metrics, potentially leading to increased operational costs and service degradation.
Mitigation strategies for CVE-2017-16113 require immediate attention from system administrators and application developers. The primary recommendation involves updating to a patched version of the parsejson module that addresses the regular expression inefficiencies. Organizations should conduct thorough vulnerability assessments to identify all applications and services that utilize the affected module. Implementing input validation and sanitization measures can provide additional protection layers, ensuring that user-supplied data is properly filtered before reaching the parsing functions. Network-level protections such as rate limiting and request timeouts can help mitigate the impact of exploitation attempts by limiting the resources available to malicious requests. Security teams should also consider implementing monitoring and alerting mechanisms to detect unusual resource consumption patterns that may indicate exploitation attempts. The remediation process must include comprehensive testing to ensure that the patch does not introduce regressions in application functionality while maintaining the intended parsing capabilities. Regular security audits and dependency management practices should be enhanced to prevent similar vulnerabilities from emerging in other third-party libraries used within the application ecosystem.