CVE-2021-3664 in url-parse
Summary
by MITRE • 07/26/2021
url-parse is vulnerable to URL Redirection to Untrusted Site
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Analysis
by VulDB Data Team • 08/05/2021
The vulnerability identified as CVE-2021-3664 affects the url-parse npm package, which is widely used for parsing and handling URLs within JavaScript applications. This package serves as a fundamental component in web development ecosystems, particularly in Node.js environments and browser-based applications that require URL manipulation and validation. The vulnerability stems from insufficient validation of URL redirection targets, creating a potential security risk when applications process user-provided or external URL inputs through this library.
The technical flaw resides in the url-parse package's handling of redirect URLs, specifically when it encounters protocols that could lead to unexpected behavior or security implications. The vulnerability allows for URL redirection to untrusted sites without proper validation, potentially enabling attackers to craft malicious URLs that could redirect users to phishing sites or other malicious destinations. This occurs when the library fails to adequately sanitize or validate the protocol and hostname components of URLs during parsing operations, particularly in scenarios involving redirects or relative URL resolution.
The operational impact of this vulnerability extends across numerous applications that depend on url-parse for URL handling, potentially affecting web applications, APIs, and backend services that process user-generated content or external links. Attackers could exploit this weakness by crafting specially formatted URLs that, when processed by vulnerable applications, would redirect users to malicious sites without proper warning or validation. This could lead to various security consequences including credential theft, malware distribution, and data exfiltration through social engineering attacks that leverage the trust users place in legitimate websites.
Organizations using the url-parse package should immediately update to the patched version to mitigate this risk, as the vulnerability could be exploited in various attack scenarios including web application attacks, man-in-the-middle scenarios, and phishing campaigns. The mitigation strategy involves not only updating the vulnerable package but also implementing additional URL validation measures within applications that process external URLs. Security teams should also consider implementing network-level protections such as web application firewalls and URL filtering mechanisms to provide additional defense in depth. This vulnerability aligns with CWE-601 and ATT&CK techniques related to URL redirection and web application attacks, emphasizing the importance of proper input validation and secure coding practices in preventing such security issues.
The broader implications of this vulnerability highlight the critical nature of dependency management in modern software development, where vulnerabilities in commonly used libraries can have widespread impact across numerous applications. Security practitioners should implement comprehensive monitoring and alerting for vulnerable dependencies, ensuring that all third-party libraries are regularly updated and that security scanning tools are integrated into development pipelines to identify and remediate such issues proactively.