CVE-2013-4457 in Cocaine
Summary
by MITRE
The Cocaine gem 0.4.0 through 0.5.2 for Ruby allows context-dependent attackers to execute arbitrary commands via a crafted has object, related to recursive variable interpolation.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 03/02/2019
The vulnerability identified as CVE-2013-4457 affects the Cocaine gem version 0.4.0 through 0.5.2 in Ruby applications, representing a critical command injection flaw that exploits recursive variable interpolation mechanisms. This vulnerability resides in the gem's handling of object serialization and variable interpolation processes, where crafted has objects can manipulate the interpolation system to execute arbitrary commands on the underlying system. The flaw specifically leverages the gem's inability to properly sanitize interpolated variables, creating a pathway for attackers to inject malicious command sequences that get executed within the application's context.
The technical implementation of this vulnerability stems from improper input validation within the Cocaine gem's interpolation logic. When the gem processes has objects containing specially crafted interpolation sequences, it fails to adequately escape or sanitize variable references that could contain command injection payloads. This recursive variable interpolation mechanism, designed for dynamic content generation, becomes exploitable when attackers can inject malicious interpolation patterns that bypass normal sanitization checks. The vulnerability operates at the intersection of object serialization and command execution contexts, where the interpolation engine processes user-controllable data without sufficient security controls.
From an operational perspective, this vulnerability presents significant risk to Ruby applications that utilize the Cocaine gem for process execution or command handling. Attackers can leverage this flaw to execute arbitrary system commands with the privileges of the application process, potentially leading to complete system compromise. The context-dependent nature of the vulnerability means that exploitation requires specific conditions where user input flows through the gem's interpolation system, making it particularly dangerous in web applications where user input is common. The impact extends beyond simple command execution to include potential data exfiltration, privilege escalation, and persistence mechanisms that attackers can employ.
Organizations using affected versions of the Cocaine gem should immediately upgrade to patched versions or implement compensating controls to mitigate this vulnerability. The recommended mitigation strategy includes applying the latest gem version that addresses the interpolation sanitization issue, implementing strict input validation for all user-controllable data that flows through the gem, and conducting thorough code reviews to identify other potential interpolation points. Security teams should also consider network-based detection measures to monitor for suspicious command execution patterns and implement application whitelisting to restrict command execution capabilities. This vulnerability aligns with CWE-78, which specifically addresses OS command injection flaws, and represents a clear violation of secure coding practices regarding input sanitization and command execution validation. The ATT&CK framework categorizes this as a command and scripting interpreter technique, with potential for privilege escalation and lateral movement within compromised environments.