CVE-2015-6375 in Networking Services for IOS
Summary
by MITRE
The debug-logging (aka debug cns) feature in Cisco Networking Services (CNS) for IOS 15.2(2)E3 allows local users to obtain sensitive information by reading an unspecified file, aka Bug ID CSCux18010.
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Analysis
by VulDB Data Team • 04/18/2018
The vulnerability identified as CVE-2015-6375 affects Cisco Networking Services (CNS) within IOS version 15.2(2)E3, specifically targeting the debug-logging functionality known as debug cns. This flaw represents a significant security weakness that enables local attackers with system-level access to extract sensitive information from the device through unauthorized file access. The vulnerability stems from improper access controls within the debug logging mechanism, which fails to adequately restrict file access permissions for authenticated local users. The unspecified file referenced in the vulnerability description likely contains configuration data, authentication credentials, or other sensitive operational information that should remain protected from unauthorized reading by local users. This issue was documented under Bug ID CSCux18010, indicating it was recognized and tracked by Cisco's internal vulnerability management systems. The vulnerability affects Cisco's networking infrastructure devices that implement the CNS feature, potentially compromising the security posture of networks relying on these platforms for routing and switching operations.
The technical implementation of this vulnerability occurs within the debug logging subsystem of the IOS operating system where the debug cns feature creates or accesses specific files containing sensitive operational data. Local users who can execute commands on the device with sufficient privileges can leverage this flaw to read files that should normally be restricted to system administrators or privileged processes only. The vulnerability essentially bypasses normal file access controls that should prevent unauthorized reading of sensitive system files. This represents a privilege escalation issue where local access can be leveraged to gain access to information that should remain confidential even within a trusted local environment. The flaw likely exists in how the debug logging subsystem handles file permissions or how it manages file descriptors for debug output storage, allowing local users to access files that contain sensitive information typically protected from casual inspection. The vulnerability is particularly concerning because it operates at the system level where local users already have significant access rights, making it a potential vector for information disclosure that could lead to further compromise.
The operational impact of CVE-2015-6375 extends beyond simple information disclosure, as the sensitive data accessible through this vulnerability could provide attackers with critical information for further exploitation attempts. The leaked information might include network configuration details, routing protocols information, authentication tokens, or other operational parameters that could be used to craft more sophisticated attacks against the network infrastructure. This vulnerability particularly affects enterprise networks where Cisco devices serve as core routing and switching infrastructure, potentially allowing attackers who have gained local access to escalate their privileges or gain deeper insights into network operations. The impact is especially severe in environments where local access controls are not properly enforced or where multiple users have access to the system. Network administrators may find that this vulnerability undermines their security assumptions about local user access controls and could potentially expose critical infrastructure information to unauthorized parties. The vulnerability also represents a potential compliance issue for organizations required to maintain strict data protection standards, as it could lead to unauthorized disclosure of sensitive network operational data.
Organizations affected by CVE-2015-6375 should implement immediate mitigations including applying the relevant Cisco security patches and updates to address the vulnerability in their IOS software. The debug-logging functionality should be disabled or properly configured with appropriate access controls to prevent unauthorized file access. Network administrators should review and tighten local access controls on affected devices, ensuring that only authorized personnel have the necessary privileges to access sensitive system information. Monitoring for unauthorized access attempts and log file analysis should be enhanced to detect potential exploitation attempts. The vulnerability aligns with CWE-200, which describes improper exposure of sensitive information, and may map to ATT&CK technique T1083 for discovering system information through local access. Organizations should also consider implementing network segmentation and access control measures to limit the potential impact of local privilege escalation attacks. Regular security assessments and vulnerability scanning should be conducted to identify similar issues in other network infrastructure components. The mitigation strategy should include both immediate patch deployment and long-term security hardening practices to prevent similar vulnerabilities from emerging in the future.