Qs versions 5.2.0 and 5.2.1 are both querystring parsing libraries designed for Node.js environments. They offer robust handling of nested objects and arrays within URL query strings, making them useful for applications that require complex data structures to be passed via URLs. Both versions are lightweight, with no runtime dependencies, simplifying integration into existing projects. They share the same permissive BSD-3-Clause license, ensuring flexibility in usage and redistribution.
The primary difference between the two versions lies in their release dates and, presumably, any bug fixes or minor improvements implemented between October 2015 (5.2.0) and July 2016 (5.2.1). While specific changelogs aren't provided, the relatively short period between releases suggests that 5.2.1 likely addresses discovered issues or offers small enhancements to the core parsing functionality of 5.2.0.
Developers choosing between these versions should favor 5.2.1, as it represents the more recent and potentially more stable iteration. The library's strength lies in its ability to parse and stringify querystrings, even those featuring deeply nested structures, a feature often lacking in more basic querystring utilities. The presence of development dependencies like lab, code, and browserify, signifies a focus on testability and browser compatibility, assuring developers of a well-maintained and reliable library. Though somewhat older versions, the continued use within the community indicates their solid performance.
All the vulnerabilities related to the version 5.2.1 of the package
Prototype Pollution Protection Bypass in qs
Affected version of qs are vulnerable to Prototype Pollution because it is possible to bypass the protection. The qs.parse function fails to properly prevent an object's prototype to be altered when parsing arbitrary input. Input containing [ or ] may bypass the prototype pollution protection and alter the Object prototype. This allows attackers to override properties that will exist in all objects, which may lead to Denial of Service or Remote Code Execution in specific circumstances.
Upgrade to 6.0.4, 6.1.2, 6.2.3, 6.3.2 or later.
qs vulnerable to Prototype Pollution
qs before 6.10.3 allows attackers to cause a Node process hang because an __ proto__ key can be used. In many typical web framework use cases, an unauthenticated remote attacker can place the attack payload in the query string of the URL that is used to visit the application, such as a[__proto__]=b&a[__proto__]&a[length]=100000000. The fix was backported to qs 6.9.7, 6.8.3, 6.7.3, 6.6.1, 6.5.3, 6.4.1, 6.3.3, and 6.2.4.
