CVE-2016-6415: Cisco IOS, IOS XR, and IOS XE IKEv1 Information Disclosure Vulnerability
What It Is – Cisco IOS, IOS XR, and IOS XE contain insufficient condition checks in the code that processes IKEv1 (Internet Key Exchange version 1) negotiation requests. An attacker can craft a malicious IKEv1 packet that forces the device to return portions of its memory.
Exploitability – The vulnerability is exploitable remotely when IKEv1 is enabled. No public exploit code has been released, but the attack requires only network access to the affected service. CVSS v3.1 base score 7.5 (High).
Affected Products – Cisco IOS, IOS XR, and IOS XE (all versions that support IKEv1).
Why It Matters for Trust & Control Assurance
- Highlights the need for continuous configuration validation to ensure insecure protocols (IKEv1) are disabled or properly hardened.
- Provides a concrete example of why control mapping and evidence collection are essential for audit readiness across frameworks (e.g., NIST CSF 2.0 Protect‑Data Security).
- Demonstrates that a single protocol flaw can undermine confidentiality controls, affecting the defensibility of a security posture presented to customers or regulators.
Recommended Actions
- Apply Cisco’s security advisory patch or upgrade to a fixed IOS release.
- If patching cannot be performed immediately, disable IKEv1 and enforce IKEv2 for all VPN tunnels.
- Enable detailed logging of IKE negotiation failures and monitor for anomalous traffic.
- Capture remediation evidence (patch version, configuration snapshots, log excerpts) to support compliance audits.
Source: CISA KEV – CVE‑2016‑6415