^{CVE-2021-1596:}Memory leak vulnerabilities in Cisco Video Surveillance 7000 Series IP Cameras' LLDP implementation allow adjacent attackers to cause denial of service conditions.

Multiple vulnerabilities exist in the Link Layer Discovery Protocol (LLDP) implementation for Cisco Video Surveillance 7000 Series IP Cameras. These vulnerabilities could allow an unauthenticated, adjacent attacker to cause a memory leak, which could lead to a denial of service (DoS) condition on affected devices. The vulnerabilities stem from incorrect processing of certain LLDP packets at ingress time. By sending crafted LLDP packets to an affected device, an attacker could cause the device to continuously consume memory, eventually leading to a crash and reload, resulting in a DoS condition. Since LLDP is a Layer 2 protocol, exploitation requires the attacker to be in the same broadcast domain as the affected device (Layer 2 adjacent).

Overview

The vulnerability (CVE-2021-1596) affects the LLDP implementation in Cisco Video Surveillance 7000 Series IP Cameras. LLDP is a vendor-neutral link layer protocol used by network devices for advertising their identity, capabilities, and neighbors on a local area network. The vulnerability is classified as CWE-401 (Memory Leak), which occurs when the camera fails to properly free allocated memory when processing certain LLDP packets. This results in a gradual consumption of available memory resources until the device becomes unstable and crashes. An attacker with Layer 2 adjacency to the affected cameras can exploit this vulnerability by sending specially crafted LLDP packets that trigger the memory leak condition.

Remediation

To address these vulnerabilities, organizations should:

1. Update affected Cisco Video Surveillance 7000 Series IP Cameras to the latest firmware version as recommended by Cisco in their security advisory.
2. If immediate patching is not possible, consider implementing network segmentation to limit which devices can communicate with the cameras at Layer 2.
3. Monitor the cameras for signs of memory exhaustion or unexpected reboots, which may indicate exploitation attempts.
4. Consider implementing access control lists (ACLs) on network switches to filter LLDP traffic to the cameras if the protocol is not required for network operations.
5. Regularly review Cisco security advisories for updates on these and related vulnerabilities.

References

1. Cisco Security Advisory: https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ipcamera-lldp-mem-wGqundTq
2. Common Weakness Enumeration (CWE-401): Memory Leak - https://cwe.mitre.org/data/definitions/401.html
3. MITRE CVE-2021-1596: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-1596
4. Cisco Video Surveillance 7000 Series IP Cameras Documentation: https://www.cisco.com/c/en/us/support/physical-security/video-surveillance-7000-series-ip-cameras/tsd-products-support-series-home.html