CVE-2013-1801 in httparty
Summary
by MITRE
The httparty gem 0.9.0 and earlier for Ruby does not properly restrict casts of string values, which might allow remote attackers to conduct object-injection attacks and execute arbitrary code, or cause a denial of service (memory and CPU consumption) by leveraging Action Pack support for YAML type conversion, a similar vulnerability to CVE-2013-0156.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 01/07/2026
The CVE-2013-1801 vulnerability represents a critical object injection flaw within the httparty gem version 0.9.0 and earlier, affecting Ruby applications that process HTTP responses containing YAML data. This vulnerability stems from insufficient input validation during type conversion processes, specifically when the gem encounters string values that should be cast to other data types. The flaw occurs in the interaction between httparty and Ruby's Action Pack framework, which provides automatic YAML type conversion capabilities that can be exploited by malicious actors.
The technical implementation of this vulnerability exploits the way httparty handles HTTP response data that contains YAML-formatted content. When the gem processes such data, it attempts to automatically convert string values into appropriate Ruby data types through Action Pack's YAML parsing mechanisms. This automatic type conversion process fails to properly sanitize or validate input, allowing attackers to inject specially crafted YAML payloads that can be deserialized into arbitrary Ruby objects. The vulnerability is particularly dangerous because it can be leveraged for remote code execution through object injection attacks, where malicious payloads are constructed to exploit the deserialization process and execute arbitrary commands on the target system.
The operational impact of CVE-2013-1801 extends beyond simple remote code execution to include significant denial of service conditions. Attackers can craft malicious payloads that cause excessive memory consumption and CPU usage during the deserialization process, leading to system resource exhaustion and potential application crashes. This vulnerability is particularly concerning in web applications where httparty is commonly used for API communication, as it can be exploited through HTTP request parameters, response headers, or any other data source that the gem processes. The similarity to CVE-2013-0156 demonstrates a pattern of vulnerabilities in Ruby's YAML handling mechanisms, indicating broader systemic issues in how Ruby applications process untrusted data.
Organizations affected by this vulnerability should immediately upgrade to httparty version 0.10.0 or later, which includes proper input validation and sanitization measures. The fix addresses the core issue by implementing stricter type casting restrictions and ensuring that string values are properly validated before any automatic conversion occurs. Security teams should also implement network-level controls such as web application firewalls to monitor and block suspicious YAML content, while conducting thorough code reviews to identify other potential uses of vulnerable libraries. This vulnerability aligns with CWE-502, which describes "Deserialization of Untrusted Data" as a critical security weakness, and maps to ATT&CK technique T1203, "Exploitation for Client Execution," as it enables attackers to execute arbitrary code on target systems through object injection attacks.
The broader implications of CVE-2013-1801 highlight the importance of proper input validation in web applications and the potential for seemingly benign library functions to become attack vectors. This vulnerability demonstrates how the integration of multiple components in Ruby applications can create unexpected security risks, particularly when automatic type conversion features are not properly secured. Organizations should implement comprehensive dependency management practices, including regular security scanning of third-party libraries and maintaining up-to-date security patches. The incident underscores the necessity of following secure coding practices and implementing defense-in-depth strategies to protect against similar vulnerabilities in other libraries and frameworks that may be susceptible to similar object injection attacks.