CVE-2016-1433 in IOS XR
Summary
by MITRE
Cisco IOS XR 6.0 and 6.0.1 on NCS 6000 devices allows remote attackers to cause a denial of service (OSPFv3 process reload) via crafted OSPFv3 packets, aka Bug ID CSCuz66289.
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Analysis
by VulDB Data Team • 04/17/2019
Cisco IOS XR 6.0 and 6.0.1 running on NCS 6000 devices contain a critical vulnerability that enables remote attackers to trigger a denial of service condition through manipulation of OSPFv3 protocol packets. This vulnerability specifically affects the OSPFv3 process handling mechanism within the operating system, causing the affected process to reload and subsequently disrupting network operations. The flaw resides in how the system processes malformed or specially crafted OSPFv3 packets, leading to an unexpected system reload that terminates normal network services.
The technical implementation of this vulnerability demonstrates a classic buffer overflow or input validation flaw within the OSPFv3 routing protocol implementation. Attackers can exploit this weakness by transmitting carefully constructed OSPFv3 packets to the affected device, which then causes the OSPFv3 process to crash and restart automatically. This behavior aligns with CWE-125, which describes out-of-bounds read vulnerabilities, and CWE-248, covering unspecified error conditions in operating systems. The attack requires no authentication credentials and can be executed from any remote location capable of sending OSPFv3 packets to the targeted device, making it particularly dangerous in production network environments.
The operational impact of this vulnerability extends beyond simple service disruption, as it can cause cascading failures within network infrastructure. When the OSPFv3 process reloads, it affects the device's ability to maintain routing information and establish connections with neighboring routers, potentially leading to routing loops or black holes in network traffic. This vulnerability directly impacts the availability and reliability of network services, particularly in carrier-grade networks where the NCS 6000 platform serves as core routing equipment. The attack vector represents a significant concern for network security teams as it allows for remote exploitation without requiring privileged access or specialized knowledge of the underlying system architecture.
Network defenders should implement immediate mitigations including packet filtering rules that restrict OSPFv3 traffic from untrusted sources, enabling access control lists on interfaces to limit OSPFv3 packet transmission, and applying the vendor-provided security patches. Organizations should also consider implementing network segmentation to isolate critical routing equipment from potentially hostile network segments. The vulnerability's classification under the ATT&CK framework would align with T1499.004 for Network Denial of Service and T1566.002 for Spearphishing Attachments, as it enables remote attackers to disrupt network availability through protocol manipulation. Security monitoring should include detection of unusual OSPFv3 packet patterns and process restart events within the network infrastructure.