CVE-2007-5162 in Ruby
Summary
by MITRE
The connect method in lib/net/http.rb in the (1) Net::HTTP and (2) Net::HTTPS libraries in Ruby 1.8.5 and 1.8.6 does not verify that the commonName (CN) field in a server certificate matches the domain name in an HTTPS request, which makes it easier for remote attackers to intercept SSL transmissions via a man-in-the-middle attack or spoofed web site.
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Analysis
by VulDB Data Team • 07/27/2019
The vulnerability described in CVE-2007-5162 represents a critical flaw in Ruby's SSL certificate validation mechanism that fundamentally undermines the security of HTTPS communications. This issue affects the Net::HTTP and Net::HTTPS libraries in Ruby versions 1.8.5 and 1.8.6, where the connect method fails to properly validate the commonName field in server certificates against the domain name specified in HTTPS requests. The vulnerability stems from the absence of hostname verification during SSL handshakes, creating a significant security gap that allows malicious actors to exploit the trust relationship between clients and servers. This flaw directly violates the fundamental principles of secure communication protocols and compromises the integrity of encrypted data transmission.
The technical implementation of this vulnerability occurs at the SSL certificate validation layer within Ruby's networking libraries, specifically in the certificate verification process that should occur during the establishment of secure connections. When Ruby's Net::HTTP and Net::HTTPS libraries establish HTTPS connections, they perform the standard SSL/TLS handshake but fail to validate that the certificate's commonName field matches the target domain name. This omission creates a scenario where an attacker can present a valid SSL certificate for a different domain, and the Ruby client will accept it without warning, effectively allowing for successful man-in-the-middle attacks. The flaw operates at the application layer rather than the transport layer, making it particularly dangerous as it bypasses the built-in security mechanisms that should protect against such attacks.
The operational impact of CVE-2007-5162 is severe and far-reaching, as it enables attackers to conduct successful man-in-the-middle attacks against any Ruby application that uses the affected Net::HTTP or Net::HTTPS libraries. This vulnerability allows adversaries to intercept sensitive data transmitted over HTTPS connections, including login credentials, personal information, and financial data. The attack surface is extensive since Ruby was widely used for web applications, API clients, and automated systems that relied on secure HTTPS communications. Organizations running Ruby applications were particularly vulnerable because the flaw existed in core networking libraries that were extensively used across the Ruby ecosystem, making the potential for exploitation widespread and difficult to track. The vulnerability also undermines the trust model that HTTPS is designed to provide, as users and applications could not reliably verify that they were communicating with the intended server.
Mitigation strategies for CVE-2007-5162 involve both immediate and long-term approaches to address the certificate validation weakness in affected Ruby installations. The most direct solution is to upgrade to Ruby versions 1.8.7 or later, where the certificate validation has been properly implemented and hostname verification is enforced. Organizations should also implement additional security measures such as certificate pinning, where applications explicitly verify certificate fingerprints rather than relying solely on certificate authorities. Network administrators should consider implementing additional monitoring to detect unusual certificate usage patterns and deploy intrusion detection systems that can identify potential man-in-the-middle attack attempts. The vulnerability aligns with CWE-295, which specifically addresses "Improper Certificate Validation," and represents a clear violation of the principle that secure communication protocols must validate the identity of communicating parties. From an ATT&CK framework perspective, this vulnerability maps to the T1046 technique of "Network Service Scanning' and T1566 'Phishing' as attackers can exploit it to establish trust relationships with malicious servers while maintaining the appearance of legitimate communications. Additionally, the flaw demonstrates the importance of proper SSL/TLS implementation and the critical need for hostname verification as outlined in various security standards and best practices for secure application development.