CVE-2016-6415 in IOS
Summary
by MITRE
The server IKEv1 implementation in Cisco IOS 12.2 through 12.4 and 15.0 through 15.6, IOS XE through 3.18S, IOS XR 4.3.x and 5.0.x through 5.2.x, and PIX before 7.0 allows remote attackers to obtain sensitive information from device memory via a Security Association (SA) negotiation request, aka Bug IDs CSCvb29204 and CSCvb36055 or BENIGNCERTAIN.
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Analysis
by VulDB Data Team • 01/27/2025
The vulnerability described in CVE-2016-6415 represents a critical information disclosure flaw within the Internet Key Exchange version 1 implementation of Cisco IOS and related operating systems. This vulnerability affects multiple Cisco IOS versions including 12.2 through 12.4, 15.0 through 15.6, IOS XE through 3.18S, IOS XR 4.3.x and 5.0.x through 5.2.x, as well as PIX software before version 7.0. The issue manifests during the Security Association negotiation process, which is a fundamental component of IPsec VPN operations where peers establish cryptographic parameters for secure communication.
The technical flaw stems from improper handling of memory contents during IKEv1 Security Association negotiation requests. When remote attackers send specially crafted SA negotiation messages to vulnerable Cisco devices, the system inadvertently reveals sensitive information from its memory buffers. This occurs because the implementation fails to properly sanitize or validate memory contents before responding to the negotiation requests. The vulnerability is classified as a memory exposure issue that directly violates the principle of least privilege and information hiding in secure system design. According to CWE classification, this corresponds to CWE-200: Exposure of Sensitive Information to an Unauthenticated Actor, which is a well-documented weakness in information security where system components inadvertently expose confidential data.
The operational impact of this vulnerability is severe and multifaceted. Attackers who successfully exploit this flaw can extract potentially sensitive information including cryptographic keys, system configuration details, network topology information, and other confidential data that may be stored in memory buffers during the negotiation process. This information disclosure could enable attackers to perform advanced persistent threats, conduct man-in-the-middle attacks, or gain deeper insights into the network infrastructure. The vulnerability is particularly concerning because it affects multiple Cisco platforms and operating systems, suggesting a widespread exposure across enterprise networks that rely on Cisco VPN solutions. From an ATT&CK framework perspective, this vulnerability aligns with T1005: Data from Local System and T1046: Network Service Scanning, as it enables adversaries to gather information about the target system and network environment.
Mitigation strategies for CVE-2016-6415 should prioritize immediate patching of affected Cisco IOS and IOS XE versions to the latest available releases that contain the necessary security fixes. Organizations should also implement network segmentation and access controls to limit exposure of vulnerable devices to untrusted networks. Monitoring for suspicious IKEv1 traffic patterns and implementing intrusion detection systems can help identify potential exploitation attempts. Additionally, organizations should conduct comprehensive network assessments to identify all affected devices and ensure that security patches are applied across all Cisco platforms. The vulnerability demonstrates the importance of proper memory management and input validation in network security implementations, reinforcing the need for rigorous security testing and code review processes in critical infrastructure software development.