CVE-2001-0752 in CBOS
Summary
by MITRE
Cisco CBOS 2.3.8 and earlier allows remote attackers to cause a denial of service via an ICMP ECHO REQUEST (ping) with the IP Record Route option set.
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Analysis
by VulDB Data Team • 06/04/2018
The vulnerability identified as CVE-2001-0752 affects Cisco CBOS versions 2.3.8 and earlier, representing a significant denial of service weakness in network infrastructure software. This flaw specifically targets the handling of ICMP ECHO REQUEST packets when the IP Record Route option is enabled, creating a condition where remote attackers can disrupt network services without requiring authentication or privileged access. The vulnerability demonstrates a critical design flaw in how the affected Cisco CBOS software processes incoming network traffic, particularly when dealing with specific IP header options that are legitimate but improperly handled by the system.
The technical implementation of this vulnerability stems from inadequate input validation within the CBOS software's network processing stack. When an attacker sends an ICMP ECHO REQUEST packet with the IP Record Route option set, the system fails to properly validate or process this specific combination of packet headers. This processing failure creates a condition where the device becomes unresponsive or crashes, effectively rendering the network service unavailable to legitimate users. The flaw operates at the network protocol level, specifically within the IP and ICMP handling mechanisms of the operating system, making it particularly dangerous as it can be exploited from outside the network perimeter without requiring any network credentials or access privileges.
The operational impact of this vulnerability extends beyond simple service disruption, as it can be leveraged to create sustained denial of service conditions that may require manual intervention to resolve. Network administrators face the challenge of identifying and mitigating attacks that can originate from anywhere on the internet, making this vulnerability particularly concerning for organizations that rely on Cisco network equipment for critical infrastructure. The vulnerability affects the availability aspect of the CIA triad, specifically targeting the network's ability to maintain continuous service delivery to authorized users. From an attack perspective, this vulnerability aligns with ATT&CK technique T1498 which involves network denial of service attacks, and represents a classic example of a resource exhaustion or system instability attack that can be executed with minimal technical expertise.
The mitigation strategies for this vulnerability involve immediate software updates to CBOS versions that address the specific packet processing flaw, along with network-level protections such as ICMP filtering and access control lists that can prevent the problematic packet types from reaching the affected systems. Organizations should implement rate limiting on ICMP traffic and consider disabling the IP Record Route option on network devices where it is not explicitly required for legitimate network operations. This vulnerability also highlights the importance of network segmentation and the principle of least privilege in network design, as limiting exposure to potentially vulnerable systems can reduce the attack surface. The issue demonstrates how seemingly benign network protocols can become attack vectors when implementations lack proper validation mechanisms, emphasizing the need for comprehensive security testing of network infrastructure software. Organizations should also consider implementing network monitoring solutions that can detect anomalous ICMP traffic patterns and alert administrators to potential exploitation attempts. This vulnerability serves as a reminder of the critical importance of maintaining up-to-date network security infrastructure and the potential consequences of running legacy software versions that contain known security flaws.