CVE-2020-3174 : Exploit Details and Defense Strategies

A vulnerability in the anycast gateway feature of Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to cause a device to learn invalid Address Resolution Protocol (ARP) entries, potentially leading to traffic disruptions.

Understanding CVE-2020-3174

This CVE involves a security flaw in Cisco NX-OS Software that could be exploited by attackers to manipulate ARP entries on a device.

What is CVE-2020-3174?

The vulnerability in Cisco NX-OS Software allows an adjacent attacker to send malicious Gratuitous ARP (GARP) packets, corrupting the ARP table on the device and leading to the population of incorrect entries.

The Impact of CVE-2020-3174

If successfully exploited, this vulnerability could result in traffic disruptions due to the device learning invalid ARP entries for nonlocal IP addresses.

Technical Details of CVE-2020-3174

This section provides more technical insights into the vulnerability.

Vulnerability Description

The vulnerability arises from improper validation of received GARP requests, enabling attackers to manipulate ARP tables.

Affected Systems and Versions

Product: Cisco NX-OS Software 7.3(2)D1(1d)
Vendor: Cisco
Version: Unspecified

Exploitation Mechanism

Attack Complexity: Low
Attack Vector: Adjacent Network
Base Score: 4.7 (Medium Severity)
Integrity Impact: Low
Privileges Required: None
User Interaction: None
Scope: Changed
Vector String: CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N

Mitigation and Prevention

Protecting systems from CVE-2020-3174 involves taking immediate steps and implementing long-term security practices.

Immediate Steps to Take

Apply vendor-provided patches or updates promptly.
Monitor network traffic for any signs of ARP table manipulation.

Long-Term Security Practices

Implement network segmentation to limit the impact of potential ARP spoofing attacks.
Regularly review and update ARP tables to ensure their accuracy.

Patching and Updates

Check for security advisories from Cisco regarding this vulnerability.
Apply recommended patches or updates to mitigate the risk of exploitation.