CVE-2017-16833 in Gemirro
Summary
by MITRE
Stored cross-site scripting (XSS) vulnerability in Gemirro before 0.16.0 allows attackers to inject arbitrary web script via a crafted javascript: URL in the "homepage" value of a ".gemspec" file.
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Analysis
by VulDB Data Team • 01/10/2023
The CVE-2017-16833 vulnerability represents a critical stored cross-site scripting flaw in the Gemirro Ruby gem management tool prior to version 0.16.0. This vulnerability resides in the handling of gem specification files, specifically within the homepage field of .gemspec files, creating a persistent security risk that affects developers and users who interact with vulnerable gem repositories. The flaw enables attackers to execute malicious JavaScript code in the context of a victim's browser when the compromised gem information is displayed, making it particularly dangerous for package managers that automatically render gem metadata.
The technical implementation of this vulnerability exploits the lack of proper input sanitization in Gemirro's processing of gem specification files. When a malicious actor creates a .gemspec file containing a crafted javascript: URL in the homepage field, the system stores this malicious content without adequate validation or escaping. Upon subsequent access to the gem information, the stored JavaScript code executes in the victim's browser context, allowing for complete session hijacking, data exfiltration, or redirection to malicious sites. This represents a classic stored XSS attack pattern where the malicious payload is persisted server-side and executed during normal user interactions with the vulnerable application.
The operational impact of CVE-2017-16833 extends beyond simple script execution, as it provides attackers with the ability to establish persistent footholds within development environments where Gemirro is deployed. Attackers can leverage this vulnerability to steal developer credentials, manipulate package installations, or redirect users to phishing sites that appear legitimate within the gem management interface. The vulnerability is particularly concerning in enterprise environments where package repositories are shared across multiple developers, as a single compromised gem can affect the entire development team. This flaw directly aligns with CWE-79 which categorizes cross-site scripting vulnerabilities, and follows ATT&CK technique T1555.003 for credential access through web application vulnerabilities.
Mitigation strategies for CVE-2017-16833 require immediate patching of Gemirro to version 0.16.0 or later, which implements proper input validation and sanitization for homepage field values in .gemspec files. Organizations should also implement additional defensive measures including content security policy enforcement, input validation at multiple layers, and regular security scanning of package repositories. The vulnerability demonstrates the importance of validating and sanitizing all user-supplied data in package management systems, as highlighted in industry best practices for secure software development lifecycle implementation. Security teams should conduct comprehensive audits of their package repositories to identify any other gems that may be vulnerable to similar stored XSS attacks, particularly those that render user-provided metadata without proper sanitization.