CVE-2020-3509 : Exploit Details and Defense Strategies
Learn about CVE-2020-3509, a vulnerability in Cisco IOS XE Software for Cisco cBR-8 Converged Broadband Routers that allows a remote attacker to cause a denial of service condition. Find out the impact, affected systems, exploitation mechanism, and mitigation steps.
A vulnerability in the DHCP message handler of Cisco IOS XE Software for Cisco cBR-8 Converged Broadband Routers could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition.
Understanding CVE-2020-3509
This CVE involves a vulnerability in Cisco IOS XE Software for Cisco cBR-8 Converged Broadband Routers that could lead to a denial of service attack.
What is CVE-2020-3509?
The vulnerability in the DHCP message handler of Cisco IOS XE Software for Cisco cBR-8 Converged Broadband Routers allows an attacker to crash the supervisor, resulting in a DoS condition.
The Impact of CVE-2020-3509
- Attack Complexity: Low
- Attack Vector: Network
- Availability Impact: High
- Base Score: 8.6 (High Severity)
- No Confidentiality or Integrity Impact
- No Privileges Required
- Scope: Changed
- User Interaction: None
Technical Details of CVE-2020-3509
This section provides detailed technical information about the vulnerability.
Vulnerability Description
The vulnerability is due to insufficient error handling when parsing DHCPv4 messages, allowing an attacker to send a malicious DHCPv4 message through a WAN interface, leading to a device reload.
Affected Systems and Versions
- Product: Cisco IOS XE Software
- Vendor: Cisco
- Affected Version: n/a
Exploitation Mechanism
An attacker can exploit this vulnerability by sending a malicious DHCPv4 message to or through a WAN interface of an affected device.
Mitigation and Prevention
Protect your systems from CVE-2020-3509 with the following steps:
Immediate Steps to Take
- Apply the necessary security patches provided by Cisco.
- Monitor network traffic for any suspicious DHCPv4 messages.
- Implement network segmentation to limit the impact of potential attacks.
Long-Term Security Practices
- Regularly update and patch all software and firmware.
- Conduct security training for network administrators to enhance awareness.
Patching and Updates
Ensure timely installation of security updates and patches to mitigate the risk of exploitation.