CVE-2017-0900 in RubyGems
Summary
by MITRE
RubyGems version 2.6.12 and earlier is vulnerable to maliciously crafted gem specifications to cause a denial of service attack against RubyGems clients who have issued a `query` command.
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Analysis
by VulDB Data Team • 05/10/2026
The vulnerability identified as CVE-2017-0900 represents a critical denial of service weakness in RubyGems versions 2.6.12 and earlier, specifically affecting clients that execute the query command. This flaw resides in the gem specification parsing mechanism where maliciously crafted gem metadata can trigger unexpected behavior in the RubyGems client software. The vulnerability stems from insufficient input validation and sanitization within the gem specification processing pipeline, allowing attackers to construct specially formatted gem specifications that disrupt normal client operations.
The technical implementation of this vulnerability exploits the query command functionality within RubyGems client software, which is commonly used by developers to search for available packages from remote repositories. When a client issues a query command, the software processes gem specifications returned by the repository server. An attacker can craft a malicious gem specification containing malformed or excessively complex metadata fields that cause the client parser to enter an infinite loop or consume excessive computational resources during parsing operations. This particular weakness maps to CWE-400, which catalogs improper handling of resource consumption issues, and specifically relates to denial of service through resource exhaustion.
The operational impact of CVE-2017-0900 extends beyond simple service disruption, as it affects the entire Ruby development ecosystem and supply chain security. Ruby developers who rely on gem repositories for package management become vulnerable to attacks that can render their development environments unusable or significantly slow down package installation and querying processes. Attackers can leverage this vulnerability to target public gem repositories, making it particularly dangerous for widely used package managers and dependency resolution systems. The attack surface includes not only individual developer workstations but also automated build systems, continuous integration pipelines, and enterprise development environments that depend on RubyGems for package management.
Mitigation strategies for this vulnerability require immediate patching of affected RubyGems versions to 2.6.13 or later, which includes enhanced input validation and resource consumption limits within the gem specification parser. Organizations should implement repository filtering mechanisms that validate gem specifications before they are processed by client software, and establish monitoring systems to detect unusual query patterns that might indicate exploitation attempts. Security practitioners should also consider implementing network segmentation and access controls around gem repositories to limit the impact of potential exploitation. The vulnerability demonstrates the importance of input validation in package management systems and aligns with ATT&CK technique T1499.004, which covers network denial of service attacks through resource exhaustion, emphasizing the need for robust resource management in software supply chain components.