CVE-2017-6627: Cisco IOS/IOS XE UDP Processing Denial‑of‑Service Vulnerability
What It Is – A flaw in the UDP packet‑processing code of Cisco IOS and IOS XE can be triggered by an unauthenticated, remote attacker. The defect causes the input queue to fill with UDP packets, wedging the interface queue and resulting in a denial‑of‑service condition.
Exploitability – The vulnerability is network‑reachable, requires no credentials, and has been publicly disclosed for several years. No public exploit code is known, but the attack vector is trivial to construct. CVSS v3.1 base score: 7.5 (High).
Affected Products – Cisco IOS and IOS XE software across a wide range of routers, switches, and firewalls (see Cisco advisory for the full product list).
Why It Matters for Trust & Control Assurance
- Continuous patch‑management evidence is a core control objective; unpatched IOS devices leave a measurable gap in that control.
- Demonstrable remediation (patches applied, version inventory updated) provides audit‑ready proof for frameworks that require vulnerability‑remediation processes.
- Real‑time monitoring of interface queues can serve as a control‑effectiveness indicator, giving stakeholders defensible evidence that the network remains resilient.
Recommended Actions
- Identify all Cisco IOS/IOS XE devices in scope and map their current software versions against Cisco’s advisory.
- Apply the vendor‑supplied patches or upgrade to a fixed release immediately.
- Enable telemetry or SNMP alerts for abnormal UDP queue growth to detect attempted exploitation.
- Record remediation steps in your change‑management system to create a verifiable audit trail.
- Update your vulnerability‑management control mapping to reflect the patched state.
Source: CISA KEV – CVE‑2017‑6627