CVE-2018-1487 in DB2
Summary
by MITRE
IBM DB2 for Linux, UNIX and Windows (includes DB2 Connect Server) 9.7, 10.1, 10.5 and 11.1 binaries load shared libraries from an untrusted path potentially giving low privilege users full access to the DB2 instance account by loading a malicious shared library. IBM X-Force ID: 140972.
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Analysis
by VulDB Data Team • 04/05/2023
IBM DB2 versions 9.7, 10.1, 10.5, and 11.1 contain a critical shared library loading vulnerability that allows low privilege users to escalate their privileges and gain full control of the DB2 instance account. This vulnerability stems from the database server's improper handling of shared library paths during the loading process, creating an attack vector where malicious actors can inject arbitrary code into the DB2 process. The flaw specifically affects the binary execution environment where the system loads shared libraries from paths that are not properly validated or secured, enabling attackers to place malicious shared libraries in directories that are searched before the legitimate system libraries. This issue represents a classic path traversal and privilege escalation vulnerability that aligns with CWE-426, which describes the insecure loading of dynamic libraries due to untrusted search paths. The vulnerability impacts all supported platforms including Linux, UNIX, and Windows operating systems, making it particularly dangerous as it affects a broad range of enterprise database deployments. Attackers can exploit this weakness by placing a malicious shared library in a directory that is searched before the legitimate system library locations, allowing them to execute arbitrary code with the elevated privileges of the DB2 instance account.
The operational impact of this vulnerability extends beyond simple privilege escalation as it provides attackers with complete control over the database instance, potentially enabling data theft, modification of database contents, or even use of the compromised database server as a pivot point for further attacks within the network infrastructure. The DB2 instance account typically runs with elevated privileges to perform database operations, and gaining access to this account essentially provides attackers with the ability to manipulate all database objects, access sensitive data, and potentially compromise the entire database environment. This vulnerability particularly affects organizations that deploy DB2 in multi-tenant environments or where database users have been granted access to database operations. The attack requires minimal privileges initially, as attackers only need access to the database system to place malicious libraries in the search path, making it a significant concern for organizations that do not properly secure their database installation directories. The vulnerability also impacts DB2 Connect Server deployments, which are commonly used for connecting to remote databases, further expanding the potential attack surface. This weakness creates a persistent threat vector that can be exploited repeatedly until properly patched, as the underlying library loading mechanism remains insecure.
Organizations should immediately implement mitigations that include restricting write access to DB2 installation directories and ensuring that shared library search paths are properly configured to avoid untrusted locations. The most effective immediate solution involves modifying the library search path to prioritize system directories over user-accessible locations, preventing the loading of malicious libraries from potentially compromised directories. System administrators should also conduct thorough security audits of DB2 installations to identify any directories that may contain user-controllable shared libraries and restrict access to these locations. IBM has released patches for this vulnerability in their security bulletins, and organizations should apply these updates as soon as possible to remediate the issue. Additionally, implementing proper access controls and privilege separation can help limit the impact of potential exploitation, as the vulnerability requires attackers to have some level of access to the system to place malicious libraries. The implementation of runtime protection mechanisms such as library integrity checking and secure library loading practices can also provide defense-in-depth protection against similar vulnerabilities. This vulnerability serves as a reminder of the critical importance of secure library loading practices and proper path validation in database systems, aligning with ATT&CK technique T1055 for privilege escalation through dynamic link library injection. Organizations should also consider implementing monitoring solutions that can detect suspicious library loading activities and alert on potential exploitation attempts.