CVE-2016-1378 in IOS
Summary
by MITRE
Cisco IOS before 15.2(2)E1 on Catalyst switches allows remote attackers to obtain potentially sensitive software-version information via a request to the Network Mobility Services Protocol (NMSP) port, aka Bug ID CSCum62591.
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Analysis
by VulDB Data Team • 07/24/2022
Cisco IOS versions prior to 15.2(2)E1 on Catalyst switches contain a vulnerability in the Network Mobility Services Protocol (NMSP) implementation that exposes sensitive software version information to remote attackers. This vulnerability resides in the NMSP port handling mechanism where the system responds to specific requests with detailed version data that should remain confidential. The flaw enables unauthenticated remote attackers to gather information about the underlying IOS software version, which can be leveraged for further exploitation activities. The vulnerability is classified as a disclosure of sensitive information through network protocol implementation, aligning with CWE-200 which addresses the exposure of sensitive information to an unauthorized actor. This type of information disclosure can significantly aid attackers in planning targeted attacks against specific IOS versions that may contain known vulnerabilities or weaknesses.
The technical implementation of this vulnerability occurs within the NMSP protocol handler of the IOS software stack. When a remote system sends a specially crafted request to the NMSP port, the switch responds with version information that includes the exact IOS build number and release details. This response contains metadata that is typically not intended for public exposure and could reveal whether the device is running a patched or vulnerable version of the software. The issue stems from inadequate input validation and response handling within the NMSP service, where the system fails to properly restrict the information returned to requesting clients. Network administrators and security professionals should note that this vulnerability affects the network infrastructure layer and can be exploited without requiring authentication credentials. The impact extends beyond simple information disclosure as it provides attackers with crucial intelligence for crafting more effective attacks against the network infrastructure.
The operational impact of CVE-2016-1378 can be significant for organizations relying on Cisco Catalyst switches as part of their network infrastructure. Attackers who successfully exploit this vulnerability can gain knowledge about the specific IOS version running on network switches, which directly impacts their ability to plan subsequent attacks. This information disclosure can lead to more targeted exploitation attempts, as attackers can identify whether their payloads are likely to be effective against the specific IOS version in use. The vulnerability creates opportunities for attackers to bypass security controls that might be designed to protect against known vulnerabilities in specific IOS versions. From an attacker's perspective, this information can be used in conjunction with other reconnaissance activities to build a comprehensive profile of the network infrastructure, potentially enabling more sophisticated attack vectors such as privilege escalation or denial of service conditions. The vulnerability also violates fundamental security principles of least privilege and information hiding that should be maintained within network infrastructure devices.
Organizations should implement immediate mitigations to address this vulnerability by upgrading to Cisco IOS version 15.2(2)E1 or later, which contains the necessary patches to prevent the information disclosure. Network segmentation and access control measures should be enforced to limit exposure of the NMSP port to trusted networks only, though this approach provides only partial protection. The vulnerability demonstrates the importance of maintaining current software versions and implementing proper network monitoring to detect unusual traffic patterns that might indicate exploitation attempts. Security teams should conduct thorough vulnerability assessments to identify all affected Catalyst switches within their network infrastructure and prioritize remediation efforts based on risk exposure. The incident highlights the need for comprehensive network security monitoring that includes protocol-level analysis to detect anomalous behavior in network services. From a compliance perspective, organizations should document their remediation efforts and maintain audit trails to demonstrate adherence to security best practices. The vulnerability also underscores the importance of implementing network access controls and restricting unnecessary network services to reduce the attack surface available to potential adversaries. This case study exemplifies how seemingly minor protocol implementation flaws can have significant security implications when they provide attackers with valuable reconnaissance information.