Learn about CVE-2023-20049 affecting Cisco ASR 9000 Series Routers, potentially leading to denial of service. Mitigate risks with security practices.
This CVE record pertains to a vulnerability in the bidirectional forwarding detection (BFD) hardware offload feature of Cisco IOS XR Software for Cisco ASR 9000 Series Aggregation Services Routers, ASR 9902 Compact High-Performance Routers, and ASR 9903 Compact High-Performance Routers, which could lead to a denial of service (DoS) condition.
Understanding CVE-2023-20049
This vulnerability affects the bidirectional forwarding detection (BFD) hardware offload feature of specific Cisco routers, potentially allowing an unauthenticated, remote attacker to disrupt services by causing a line card to reset.
What is CVE-2023-20049?
CVE-2023-20049 involves the mishandling of malformed BFD packets on line cards with the BFD hardware offload feature enabled. An attacker could exploit this flaw by sending a specially crafted IPv4 BFD packet to the targeted device, leading to line card exceptions or a hard reset, causing traffic loss until the line card reloads.
The Impact of CVE-2023-20049
The vulnerability's impact is significant, with an attacker capable of triggering line card resets and disrupting services, potentially leading to downtime and service unavailability for affected devices.
Technical Details of CVE-2023-20049
This section delves into the specifics of the vulnerability, outlining key details for understanding and addressing the issue effectively.
Vulnerability Description
The vulnerability arises due to the incorrect handling of malformed BFD packets on line cards with the BFD hardware offload feature enabled, allowing attackers to disrupt services and cause denial of service conditions.
Affected Systems and Versions
The affected products include Cisco IOS XR Software for ASR 9000 Series Routers, specifically impacting versions with the BFD hardware offload feature enabled.
Exploitation Mechanism
By sending a maliciously crafted IPv4 BFD packet to a vulnerable device, attackers can exploit the vulnerability, leading to line card exceptions or hard resets that disrupt traffic until the affected line card reloads.
Mitigation and Prevention
To mitigate the risks associated with CVE-2023-20049, it is crucial to implement immediate steps and long-term security practices to enhance the overall security posture of the network and devices.
Immediate Steps to Take
Long-Term Security Practices
Patching and Updates