CVE-2024-27281 is a vulnerability affecting RDoc versions 6.3.3 through 6.6.2, which are distributed with Ruby versions 3.x through 3.3.0. The issue stems from the way RDoc parses .rdoc_options files and documentation cache files as YAML without restricting the classes that can be deserialized. This lack of restriction enables an attacker to perform object injection, which can lead to remote code execution (RCE) when the malicious YAML content is processed. Specifically, when RDoc loads the documentation cache or parses configuration files, it can deserialize arbitrary objects, potentially executing attacker-controlled code. The vulnerability is classified under CWE-502 (Deserialization of Untrusted Data). Exploitation requires local access to the system and user interaction to trigger the parsing of a crafted .rdoc_options or cache file. The CVSS v3.1 base score is 4.5 (medium), reflecting the high attack complexity and the need for user interaction, but no privileges are required to exploit it. Fixed versions have been released: RDoc 6.6.3.1 for Ruby 3.3.0, 6.3.4.1 for Ruby 3.0, 6.4.1.1 for Ruby 3.1, and 6.5.1.1 for Ruby 3.2. No known exploits have been reported in the wild to date. The vulnerability primarily threatens environments where untrusted users can influence RDoc configuration or cache files, such as shared development environments or CI/CD pipelines that use Ruby documentation generation.

For European organizations, the impact of CVE-2024-27281 depends on the extent of Ruby and RDoc usage in their software development and deployment environments. Organizations that use Ruby 3.x versions with affected RDoc versions in development, testing, or production could face risks of remote code execution if an attacker can supply malicious .rdoc_options or documentation cache files. This could lead to unauthorized code execution, potentially compromising confidentiality, integrity, and availability of systems. The vulnerability is particularly concerning in multi-user environments, shared build servers, or CI/CD pipelines where untrusted users might inject malicious YAML content. Although exploitation requires local access and user interaction, the ability to execute arbitrary code remotely can facilitate lateral movement or privilege escalation within an organization’s network. European companies in sectors with heavy software development activities, such as finance, telecommunications, and technology, may face higher risks. The medium severity rating suggests a moderate but not critical threat, emphasizing the need for timely patching to prevent exploitation.

To mitigate CVE-2024-27281, European organizations should: 1) Upgrade RDoc to the fixed versions corresponding to their Ruby version (6.6.3.1 for Ruby 3.3.0, 6.3.4.1 for Ruby 3.0, 6.4.1.1 for Ruby 3.1, and 6.5.1.1 for Ruby 3.2) as soon as possible. 2) Restrict write permissions on .rdoc_options and documentation cache files to trusted users only, preventing untrusted users from injecting malicious YAML content. 3) Implement strict access controls and monitoring on build servers, CI/CD pipelines, and shared development environments to detect and prevent unauthorized file modifications. 4) Use containerization or sandboxing for documentation generation processes to limit the impact of potential code execution. 5) Audit existing YAML parsing configurations and consider applying safe YAML loading practices that restrict deserialization to known safe classes. 6) Educate developers and DevOps teams about the risks of deserializing untrusted YAML data and enforce secure coding practices. 7) Monitor security advisories for any emerging exploits or additional patches related to this vulnerability.