CVE-2019-1598 : Security Advisory and Response

Multiple vulnerabilities in the implementation of the Lightweight Directory Access Protocol (LDAP) feature in Cisco FXOS Software and Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition.

Understanding CVE-2019-1598

This CVE identifies vulnerabilities in the LDAP feature of Cisco FXOS Software and Cisco NX-OS Software that could be exploited by remote attackers to trigger a DoS attack.

What is CVE-2019-1598?

The vulnerabilities in the LDAP feature of Cisco FXOS Software and Cisco NX-OS Software allow unauthenticated remote attackers to force affected devices to reload, leading to a DoS condition. The weaknesses stem from improper parsing of LDAP packets by the affected devices.

The Impact of CVE-2019-1598

The vulnerabilities could be exploited by sending specifically crafted LDAP packets to the targeted device, causing a DoS by forcing the device to reload. The attack requires the LDAP packet to originate from an LDAP server configured on the targeted device.

Technical Details of CVE-2019-1598

The technical details of this CVE provide insight into the vulnerability, affected systems, and exploitation mechanisms.

Vulnerability Description

The vulnerabilities result from the improper parsing of LDAP packets by affected devices, allowing remote attackers to exploit the weaknesses.

Affected Systems and Versions

Firepower 4100 Series Next-Generation Firewalls (versions prior to 2.0.1.201, 2.2.2.54, and 2.3.1.75)
Firepower 9300 Security Appliances (versions prior to 2.0.1.201, 2.2.2.54, and 2.3.1.75)
MDS 9000 Series Multilayer Switches (versions prior to 8.2(1))
Nexus 3000 Series Switches (versions prior to 7.0(3)I7(1))
Nexus 3500 Platform Switches (versions prior to 7.0(3)I7(2))
Nexus 7000 and 7700 Series Switches (versions prior to 6.2(20), 7.3(2)D1(1), and 8.2(1))
Nexus 9000 Series Switches in Standalone NX-OS Mode (versions prior to 7.0(3)I7(1))
UCS 6200 and 6300 Fabric Interconnect (versions prior to 3.2(2b))

Exploitation Mechanism

The attacker can exploit the vulnerabilities by sending a specifically crafted LDAP packet following Basic Encoding Rules (BER) to the targeted device, originating from an LDAP server configured on the device.

Mitigation and Prevention

To address CVE-2019-1598, immediate steps and long-term security practices are essential.

Immediate Steps to Take

Apply vendor-provided patches and updates promptly.
Implement network segmentation to limit the impact of potential attacks.
Monitor network traffic for any suspicious LDAP activities.

Long-Term Security Practices

Regularly update and patch all software and firmware on network devices.
Conduct regular security assessments and penetration testing to identify vulnerabilities.
Educate users and administrators on best security practices to prevent unauthorized access.

Patching and Updates

Cisco has released patches to address the vulnerabilities. Ensure all affected systems are updated with the latest security fixes.