CVE-2021-1587: cisco cisco nx-os software Misinterpretation of Input

Vulnerability summary

CVE-2021-1587 is a high (CVSS 8.6) Misinterpretation of Input vulnerability in cisco cisco nx-os software. EPSS estimates a 1.68% chance of exploitation in the next 30 days, higher than 76.5% of scored vulnerabilities.

Timeline

1. 25-08-2021
   PublishedVulnerability first disclosed.
2. 07-11-2024
   Last modifiedVulnerability information updated.

Description

A vulnerability in the VXLAN Operation, Administration, and Maintenance (OAM) feature of Cisco NX-OS Software, known as NGOAM, could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper handling of specific packets with a Transparent Interconnection of Lots of Links (TRILL) OAM EtherType. An attacker could exploit this vulnerability by sending crafted packets, including the TRILL OAM EtherType of 0x8902, to a device that is part of a VXLAN Ethernet VPN (EVPN) fabric. A successful exploit could allow the attacker to cause an affected device to experience high CPU usage and consume excessive system resources, which may result in overall control plane instability and cause the affected device to reload. Note: The NGOAM feature is disabled by default.

• CWE-115Misinterpretation of InputThe product misinterprets an input, whether from an attacker or another product, in a security-relevant fashion.
• CWE-436Interpretation ConflictProduct A handles inputs or steps differently than Product B, which causes A to perform incorrect actions based on its perception of B's state.