CVE-2024-20304 - Unauthenticated Remote Attacker Can Exhaust UDP Packet Memory of Cisco IOS XR Software via Mtrace2 Vulnerability

A newly discovered vulnerability, CVE-2024-20304, affects the multicast traceroute version 2 (Mtrace2) feature of Cisco IOS XR Software. This vulnerability allows an unauthenticated remote attacker to exhaust the UDP packet memory of an affected device, potentially causing a denial of service (DoS) condition.

Vulnerability Details

The vulnerability exists in the Mtrace2 feature of Cisco IOS XR Software, as the code does not properly handle packet memory. As a result, an attacker can exploit this vulnerability by sending crafted packets to the affected device.

This vulnerability can be exploited using either IPv4 or IPv6 packets, making it more versatile for potential attackers. A successful exploit could exhaust the incoming UDP packet memory on the targeted device, which in turn would prevent the device from processing higher-level UDP-based protocols packets. This could lead to a possible denial of service (DoS) condition.

Code Snippet

In the Mtrace2 implementation of Cisco IOS XR Software, the improper handling of packet memory could be represented as follows:

void process_packet(packet_t *pkt)
{
    ...
    // Memory is not properly released, leading to potential exhaustion
    if (check_packet(pkt) == INVALID) {
        return; // Memory leak occurs here
    }
    ...
}

For more information on this vulnerability, please refer to the following official resources

1. Cisco Security Advisory - CVE-2024-20304
2. NIST National Vulnerability Database - CVE-2024-20304
3. Common Vulnerabilities and Exposures - CVE-2024-20304

Exploit Details

An attacker could exploit this vulnerability by crafting malicious packets and sending them to the target device. These packets could carry various payloads, including those specifically targeting Mtrace2 functions or other UDP-based protocols.

Since this vulnerability is present in both IPv4 and IPv6 implementations, an attacker could target either protocol, adding to the potential impact. This type of exploit typically does not require authentication, making it accessible to various malicious actors.

The following is a simple example of how an attacker might craft a packet to exploit this vulnerability:

import socket

# Craft a malicious packet targeting Mtrace2
def create_malicious_packet():
    ...
    return malicious_packet

# Send the crafted packet to the target device
def exploit(target_ip):
    packet = create_malicious_packet()

    # Create a socket using IPv4 or IPv6
    s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    
    # Send the malicious packet
    s.sendto(packet, (target_ip, mtrace2_port))
    s.close()

# Example usage
target_device_ip = "192..2.1"
exploit(target_device_ip)

To protect against this vulnerability, it is recommended for users to update their Cisco IOS XR Software to a version that includes the necessary patch.

In conclusion, the Mtrace2 vulnerability CVE-2024-20304 poses a significant risk to affected Cisco devices. Users should take immediate steps to update and secure their systems against potential exploitation.

Timeline

Published on: 09/11/2024 17:15:11 UTC
Last modified on: 09/12/2024 12:35:54 UTC