CVE-2023-26021 Explained : Impact and Mitigation

This is a detailed overview of CVE-2023-26021, providing insights into the vulnerability, its impact, technical details, and mitigation strategies.

Understanding CVE-2023-26021

CVE-2023-26021 refers to a vulnerability in IBM Db2 for Linux, UNIX, and Windows versions 11.1 and 11.5 that could lead to a denial of service attack. The vulnerability arises when the server crashes while compiling a specially crafted SQL query using a LIMIT clause.

What is CVE-2023-26021?

The vulnerability in IBM Db2 for Linux, UNIX, and Windows (including Db2 Connect Server) versions 11.1 and 11.5 allows threat actors to exploit a flaw that causes the server to crash, resulting in a denial of service. The vulnerability is categorized under CWE-20: Improper Input Validation.

The Impact of CVE-2023-26021

With a CVSS v3.1 base score of 7.5, the impact of CVE-2023-26021 is considered high. As the availability impact is rated as high, threat actors can exploit the vulnerability over the network without requiring any privileges, potentially disrupting the Db2 server's operations.

Technical Details of CVE-2023-26021

The vulnerability stems from improper input validation, particularly in the compilation of SQL queries using a LIMIT clause in IBM Db2 versions 11.1 and 11.5.

Vulnerability Description

The flaw allows attackers to trigger a denial of service condition by submitting a specially crafted SQL query to the server, leading it to crash during compilation.

Affected Systems and Versions

Product: DB2 for Linux, UNIX, and Windows
Vendor: IBM
Affected Versions: 11.1, 11.5

Exploitation Mechanism

Threat actors can exploit the vulnerability by sending malicious SQL queries containing a specific syntax using the LIMIT clause to the affected IBM Db2 servers, causing them to crash.

Mitigation and Prevention

It is crucial to take immediate and proactive steps to mitigate the risks associated with CVE-2023-26021 and prevent potential exploitation.

Immediate Steps to Take

Monitor vendor resources for security advisories and patches related to the vulnerability.
Apply security updates and patches released by IBM for affected Db2 versions.
Implement network security measures to restrict unauthorized access to Db2 servers.

Long-Term Security Practices

Regularly update and maintain the Db2 server to ensure the latest security enhancements are applied.
Conduct periodic vulnerability assessments and penetration testing to identify and address security gaps.
Educate database administrators and users on secure coding practices to prevent similar vulnerabilities.

Patching and Updates

To address CVE-2023-26021, users should refer to the vendor advisory from IBM (https://www.ibm.com/support/pages/node/6985681) for specific instructions on applying patches and updates to mitigate the vulnerability.