Denial-of-Service Vulnerability (CVE‑2018‑0154) in Cisco IOS ISM‑VPN Allows Remote Unauthenticated Disruption
What It Is — A flaw in the crypto engine of Cisco’s Integrated Services Module for VPN (ISM‑VPN) running on Cisco IOS Software permits an unauthenticated, remote attacker to trigger a denial‑of‑service condition. The vulnerability is tracked as CVE‑2018‑0154 and carries a CVSS v3.1 base score of 7.5 (High).
Exploitability — No public exploit code has been released, but the vulnerability can be triggered simply by sending specially‑crafted VPN traffic to an affected device; exploitation does not require authentication.
Affected Products — Cisco IOS Software Integrated Services Module for VPN (ISM‑VPN) on any Cisco router or switch that runs the vulnerable IOS version.
Why It Matters for Trust & Control Assurance
- Demonstrates the need for continuous patch‑management monitoring; evidence of timely remediation is a core control for audit readiness.
- Highlights the importance of network‑device logging and alerting to detect abnormal VPN traffic that could indicate an attempted DoS.
- Provides a concrete test case for the control objective “Maintain up‑to‑date software and verify remediation evidence”, which maps to multiple frameworks (e.g., NIST CSF, ISO 27001).
Recommended Actions
- Review Cisco’s advisory and apply the released IOS patches or recommended mitigations immediately.
- Verify that patch deployment is recorded in your configuration‑management system to generate defensible audit evidence.
- Enable detailed VPN logging and integrate logs into a SIEM for real‑time detection of abnormal traffic patterns.
- Update your vulnerability‑management dashboard to flag this CVE and track remediation status.
Source: CISA KEV – CVE‑2018‑0154