CVE-2013-2233 in Ansible
Summary
by MITRE
Ansible before 1.2.1 makes it easier for remote attackers to conduct man-in-the-middle attacks by leveraging failure to cache SSH host keys.
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Analysis
by VulDB Data Team • 03/08/2023
The vulnerability identified as CVE-2013-2233 affects Ansible versions prior to 1.2.1 and represents a significant security weakness in the automation framework's SSH host key verification process. This flaw creates an exploitable condition that allows remote attackers to conduct man-in-the-middle attacks by exploiting the software's failure to properly cache SSH host keys during connection establishment. The vulnerability directly impacts the integrity of SSH communications within Ansible's infrastructure, undermining the trust model that secure remote administration relies upon. When Ansible fails to cache SSH host keys, it cannot effectively verify the identity of target systems, leaving automated deployments susceptible to interception and manipulation by malicious actors positioned between the Ansible control node and target hosts.
The technical implementation of this vulnerability stems from Ansible's handling of SSH connections in its inventory management and remote execution processes. In versions before 1.2.1, Ansible does not maintain persistent SSH host key caches, which means that each SSH connection attempt requires the system to fetch and verify host keys from scratch. This process creates a window of opportunity for attackers to intercept SSH connections and present forged host keys to the Ansible client. The flaw specifically relates to how Ansible manages the SSH known_hosts file and host key verification mechanisms, allowing attackers to exploit the lack of proper key caching to establish unauthorized communication channels. This vulnerability is categorized under CWE-310 as "Cryptographic Issues" and more specifically aligns with CWE-319 which addresses "Clear Text Transmission of Sensitive Information" and CWE-295 which covers "Improper Certificate Validation."
The operational impact of CVE-2013-2233 extends beyond simple network interception, as it fundamentally compromises the security posture of automated infrastructure management systems. Organizations using vulnerable Ansible versions face risks including unauthorized access to target systems, data exfiltration, and potential lateral movement within their network infrastructure. The vulnerability is particularly dangerous in environments where Ansible is used for critical infrastructure management, patch deployment, and configuration management, as attackers could manipulate automated processes to execute malicious commands or alter system configurations. The man-in-the-middle attack vector allows threat actors to potentially gain persistent access to systems that would otherwise be protected by SSH key authentication, making this vulnerability especially concerning for security-conscious organizations. According to ATT&CK framework, this vulnerability maps to T1021.004 (SSH) and T1566.001 (Phishing for Information) as attackers could leverage the compromised communication channel to further their objectives.
Mitigation strategies for CVE-2013-2233 primarily involve upgrading to Ansible version 1.2.1 or later, which includes proper SSH host key caching mechanisms. Organizations should also implement additional security controls such as enabling strict SSH host key checking, configuring proper known_hosts file management, and implementing network-level protections including firewalls and intrusion detection systems. Security teams should conduct comprehensive inventory assessments to identify all systems running vulnerable Ansible versions and establish remediation schedules prioritized by risk exposure. The implementation of SSH key management best practices, including regular key rotation and proper host key verification procedures, should be enforced across all automated deployment environments. Additionally, organizations should consider implementing network segmentation and monitoring solutions to detect anomalous SSH traffic patterns that might indicate exploitation attempts. The vulnerability serves as a reminder of the critical importance of maintaining secure communication channels in automation frameworks and demonstrates how seemingly minor implementation flaws can create significant security risks in enterprise environments.