CVE-2019-1963 : Security Advisory and Response

Cisco FXOS and NX-OS Software Authenticated Simple Network Management Protocol Denial of Service Vulnerability

Understanding CVE-2019-1963

This CVE involves a flaw in the input packet processor for SNMP in Cisco FXOS Software and Cisco NX-OS Software, potentially allowing a remote attacker to restart the SNMP application on affected devices.

What is CVE-2019-1963?

The vulnerability stems from insufficient scrutiny of ASN.1-encoded variables within SNMP packets, enabling an authenticated attacker to trigger multiple restarts of the SNMP application, leading to a system-wide restart and a denial of service situation.

The Impact of CVE-2019-1963

The vulnerability has a CVSS base score of 7.7, indicating a high severity issue with a significant impact on availability.

Technical Details of CVE-2019-1963

This section provides more in-depth technical insights into the vulnerability.

Vulnerability Description

The flaw allows a remote attacker to exploit SNMP input packet processor, causing unexpected restarts of the SNMP application on affected devices.

Affected Systems and Versions

Product: Cisco Unified Computing System (Managed)
Vendor: Cisco
Versions Affected: Less than 8.4(1)

Exploitation Mechanism

Attacker needs to be authenticated
Crafted SNMP packet sent to SNMP daemon triggers the exploit
Results in multiple restarts of SNMP application and system-wide restart

Mitigation and Prevention

Steps to address and prevent exploitation of CVE-2019-1963.

Immediate Steps to Take

Apply vendor-provided patches or updates promptly
Monitor network traffic for any suspicious SNMP packets
Restrict SNMP access to trusted sources

Long-Term Security Practices

Regularly update and patch all software and firmware
Implement network segmentation to limit the impact of potential attacks
Conduct regular security audits and assessments

Patching and Updates

Refer to the vendor's security advisory for specific patch details and instructions