CVE-2015-4205: Cisco IOS XR 5.3.1 on ASR 9000 devices allows remote attackers to cause a denial of service (NPU chip reset...

Security readout for executives and security teams

This vulnerability can let someone on the same local network disrupt affected Cisco ASR 9000 routers running IOS XR 5.3.1. The reported impact is denial of service through an NPU chip reset or line-card reload, which can affect network availability for dependent services. Exposure is most relevant where affected ASR 9000 interfaces are reachable from untrusted or poorly controlled Layer 2 segments. Internet-only exposure is not established by the provided sources because the trigger requires local-network frame delivery. Treat this as an availability risk for critical network infrastructure. Urgency rises if ASR 9000 routers are in production aggregation paths and share local segments with untrusted devices. Confirm exposure and vendor remediation before scheduling change windows. Mitigation focus: Identify ASR 9000 routers running Cisco IOS XR 5.3.1.; Review Cisco advisory 39455 for fixed software or official workarounds.; Restrict untrusted Layer 2 access to router-facing network segments..

Prepared

Jun 13, 2026, 22:39 UTC (UTC+00:00)

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.