CVE-2019-16019 : Exploit Details and Defense Strategies
Learn about CVE-2019-16019 involving Cisco IOS XR Software BGP EVPN vulnerabilities leading to denial of service. Understand the impact, technical details, and mitigation steps.
Cisco IOS XR Software BGP EVPN Denial of Service Vulnerabilities
Understanding CVE-2019-16019
This CVE involves multiple vulnerabilities in the implementation of Border Gateway Protocol (BGP) Ethernet VPN (EVPN) functionality in Cisco IOS XR Software, potentially leading to a denial of service (DoS) scenario.
What is CVE-2019-16019?
The vulnerabilities in Cisco IOS XR Software stem from the mishandling of BGP update messages containing manipulated EVPN attributes. Unauthorized attackers could exploit these flaws by sending BGP EVPN update messages with incorrect attributes to a targeted system, causing the BGP process to restart unexpectedly and resulting in a DoS situation.
The Impact of CVE-2019-16019
- CVSS Score: 8.6 (High Severity)
- Attack Vector: Network
- Availability Impact: High
- These vulnerabilities do not require privileges for exploitation but can lead to a significant impact on system availability.
Technical Details of CVE-2019-16019
This section delves into the specific technical aspects of the vulnerability.
Vulnerability Description
The vulnerabilities arise from the incorrect processing of BGP update messages with crafted EVPN attributes, allowing attackers to disrupt the BGP process and trigger a DoS condition.
Affected Systems and Versions
- Affected Product: Cisco IOS XR Software
- Vendor: Cisco
- Affected Version: Not Applicable (n/a)
Exploitation Mechanism
- Attackers need to send BGP EVPN update messages with malformed attributes to exploit the vulnerabilities.
- The attacker must have access to a valid, configured BGP peer or inject the malicious update into the victim's BGP network through a legitimate TCP connection.
Mitigation and Prevention
Protecting systems from CVE-2019-16019 requires immediate actions and long-term security practices.
Immediate Steps to Take
- Apply vendor-provided patches or updates to mitigate the vulnerabilities.
- Monitor BGP traffic for any suspicious activity or malformed attributes.
Long-Term Security Practices
- Regularly update and patch network devices to address known vulnerabilities.
- Implement network segmentation and access controls to limit the impact of potential attacks.
Patching and Updates
- Cisco has likely released patches or updates to address the vulnerabilities. Ensure timely application of these fixes to secure the affected systems.