CVE-2018-11752 in cisco_ios
Summary
by MITRE
Previous releases of the Puppet cisco_ios module output SSH session debug information including login credentials to a world readable file on every run. These issues have been resolved in the 0.4.0 release.
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Analysis
by VulDB Data Team • 03/28/2020
The vulnerability identified as CVE-2018-11752 affects the Puppet cisco_ios module, a widely used configuration management tool for network device management. This issue represents a critical security flaw that exposed sensitive authentication credentials through improper logging mechanisms. The vulnerability specifically impacted versions of the module prior to 0.4.0, where the software failed to properly sanitize debug output during SSH session establishment with cisco network devices. The flaw allowed for credential exposure through world-readable log files, creating a significant attack surface for unauthorized personnel who could access these sensitive materials.
The technical implementation of this vulnerability stems from the module's handling of SSH session debug information within its codebase. During normal operation, the Puppet cisco_ios module establishes secure connections to Cisco network devices using SSH protocols, which inherently requires authentication credentials. However, the module's debug logging functionality inadvertently captured and wrote these credentials to log files without proper access controls or credential sanitization. This design flaw resulted in sensitive information including usernames and passwords being stored in files accessible to all system users, effectively removing any privilege-based access restrictions that should have protected this data.
The operational impact of this vulnerability extends beyond simple credential exposure, as it fundamentally undermines the security posture of organizations relying on Puppet for network device management. Network administrators who depend on this module for configuration automation face potential compromise of their entire network infrastructure when credentials are exposed in world-readable files. The vulnerability aligns with CWE-200, which describes improper exposure of sensitive information, and represents a direct violation of the principle of least privilege in information security. Attackers with access to the system could easily retrieve these credentials and potentially gain unauthorized access to Cisco network devices, enabling further exploitation through lateral movement and privilege escalation attacks.
The remediation for this vulnerability required the development team to implement proper credential sanitization and access control measures in the module's logging mechanisms. Version 0.4.0 addressed the issue by ensuring that debug output no longer includes sensitive authentication information and by implementing proper file access controls for log files. Organizations should immediately upgrade to the patched version and conduct thorough audit procedures to identify and remove any previously exposed credential information from world-readable files. The solution aligns with ATT&CK technique T1078 which covers valid accounts and T1566 which covers credential access through various attack vectors. Security teams should also implement monitoring for similar logging practices across their infrastructure to prevent analogous vulnerabilities in other modules or applications that handle sensitive authentication data.