CVE-2020-4976 in DB2
Summary
by MITRE • 03/11/2021
IBM DB2 for Linux, UNIX and Windows (includes DB2 Connect Server) 9.7, 10.1, 10.5, 11.1, and 11.5 could allow a local user to read and write specific files due to weak file permissions. IBM X-Force ID: 192469.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 03/31/2021
IBM DB2 database server versions 9.7, 10.1, 10.5, 11.1, and 11.5 contain a critical file permission vulnerability that affects local users with minimal privileges. This weakness stems from improper file access controls within the database installation directories, allowing unauthorized users to manipulate sensitive configuration files and data structures. The vulnerability manifests when the database service runs with elevated privileges and creates files with overly permissive access rights, enabling local users to read and write to specific system files that should remain restricted. This issue represents a classic privilege escalation vector that directly violates the principle of least privilege and can be categorized under CWE-732, which specifically addresses incorrect permissions for critical resources. The affected IBM DB2 Connect Server component further amplifies the risk by providing additional attack surface through its network connectivity features. The operational impact of this vulnerability extends beyond simple file access, as local attackers can potentially modify database configuration parameters, access sensitive credentials stored in configuration files, and manipulate database metadata. This weakness creates opportunities for attackers to establish persistent access or escalate privileges to gain administrative control over the database system. According to the ATT&CK framework, this vulnerability aligns with T1068, which covers the use of local privilege escalation techniques, and T1078, which addresses valid accounts and legitimate credentials. The vulnerability is particularly concerning because it does not require network access or authentication to exploit, making it an attractive target for attackers who have already gained initial access to the system. The weak file permissions typically affect installation directories, log files, configuration files, and temporary storage areas where database processes store sensitive information. Attackers can leverage this flaw to extract database connection strings, administrative credentials, and other sensitive data that may be stored in plain text within these files. The IBM X-Force ID 192469 indicates the vulnerability was recognized by IBM security teams and prioritized for remediation. Organizations running these affected DB2 versions face significant risk of data compromise and system integrity violations, especially in environments where multiple users share the same system or where database servers are not properly segmented from general user access. The vulnerability demonstrates poor security hygiene in the default installation process, where security considerations are not properly implemented during system setup. This type of flaw commonly occurs in enterprise database systems where the focus on functionality and performance overshadows security configuration defaults. The remediation typically requires applying the appropriate IBM security patches or updating to supported versions where proper file permissions have been implemented. System administrators should conduct comprehensive audits of file permissions across all DB2 installation directories and implement mandatory access controls to prevent unauthorized file access. Additionally, regular security assessments should be performed to ensure that default installations do not expose sensitive system components to unnecessary access rights. The vulnerability underscores the importance of proper privilege management and secure configuration practices in database deployments, particularly in multi-user environments where the principle of least privilege must be strictly enforced. Organizations should implement robust monitoring solutions to detect unauthorized file access attempts and ensure that database systems are properly hardened against local privilege escalation attacks. The impact of this vulnerability can be mitigated through proper system hardening, regular security updates, and adherence to security best practices for database server configurations.