CVE-2017-20162 in vercel
Summary
by MITRE • 01/09/2023
A vulnerability, which was classified as problematic, has been found in vercel ms up to 1.x. This issue affects the function parse of the file index.js. The manipulation of the argument str leads to inefficient regular expression complexity. The attack may be initiated remotely. The exploit has been disclosed to the public and may be used. Upgrading to version 2.0.0 is able to address this issue. The patch is named caae2988ba2a37765d055c4eee63d383320ee662. It is recommended to upgrade the affected component. The associated identifier of this vulnerability is VDB-217451.
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Analysis
by VulDB Data Team • 11/05/2025
The vulnerability identified as CVE-2017-20162 represents a critical security flaw in the vercel ms library version 1.x, specifically within the parse function located in index.js. This issue stems from inefficient regular expression complexity that can be exploited through manipulation of the str argument parameter. The vulnerability's classification as problematic indicates significant security implications that warrant immediate attention from system administrators and security teams. The affected library is commonly used for parsing time durations and string representations of time values, making it a widely deployed component across various applications and services that depend on accurate time parsing functionality.
The technical root cause of this vulnerability lies in the improper implementation of regular expressions within the parse function, which creates exponential time complexity during pattern matching operations. When an attacker provides a specially crafted string input to the str argument, the regular expression engine can be forced into a state of catastrophic backtracking, where the processing time increases exponentially with input length. This behavior directly maps to CWE-1333, which specifically addresses inefficient regular expression complexity that can lead to denial of service attacks. The vulnerability's remote exploitation capability means that attackers can trigger this condition through network-based inputs without requiring local access to the target system, making it particularly dangerous in web applications and services.
The operational impact of this vulnerability extends beyond simple denial of service scenarios to potentially enable more sophisticated attack vectors. When exploited, the inefficient regular expression complexity can cause significant resource consumption, leading to system performance degradation or complete service unavailability. Attackers can leverage this vulnerability to perform resource exhaustion attacks against applications that utilize the affected library, potentially causing cascading failures in larger systems. The public disclosure of this exploit increases the risk profile significantly, as malicious actors can readily implement the attack without requiring advanced technical knowledge. This vulnerability affects any system that relies on the vercel ms library for time parsing operations, including web applications, microservices, and backend systems that process time-related data.
Mitigation of this vulnerability requires immediate action to upgrade the affected vercel ms library to version 2.0.0, which contains the necessary patch identified by the commit hash caae2988ba2a37765d055c4eee63d383320ee662. System administrators should conduct comprehensive inventory checks to identify all instances of the vulnerable library across their infrastructure and implement the upgrade process as quickly as possible. The patch addresses the underlying regular expression implementation to prevent catastrophic backtracking scenarios and improve overall performance characteristics. Organizations should also consider implementing input validation measures and rate limiting mechanisms as additional defensive strategies to minimize the potential impact of similar vulnerabilities. This vulnerability aligns with ATT&CK technique T1499.004, which involves network denial of service attacks through resource exhaustion, and represents a common pattern of vulnerabilities that can be exploited in modern web applications and cloud environments where time parsing functionality is extensively used.