CVE-2005-4866 in DB2
Summary
by MITRE
Stack-based buffer overflow in JDBC Applet Server in IBM DB2 8.1 allows remote attackers to execute arbitrary by connecting and sending a long username, then disconnecting gracefully and reconnecting and sending a short username and an unexpected db2java.zip version, which causes a null terminator to be removed and leads to the overflow.
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Analysis
by VulDB Data Team • 08/02/2019
The vulnerability described in CVE-2005-4866 represents a critical stack-based buffer overflow affecting IBM DB2 8.1 JDBC Applet Server component. This flaw exists within the database server's handling of client connections and authentication sequences, specifically when processing username parameters and version information during the connection lifecycle. The vulnerability demonstrates a complex interaction between multiple protocol states and memory management behaviors that ultimately leads to arbitrary code execution capabilities for remote attackers. The flaw exploits the server's improper handling of string termination and memory boundaries during connection state transitions, creating conditions where attacker-controlled data can overwrite critical stack memory locations.
The technical implementation of this vulnerability involves a sophisticated multi-stage attack pattern that leverages the JDBC Applet Server's connection handling logic. Attackers must first establish a connection with a deliberately crafted long username that triggers memory allocation patterns leading to buffer boundary conditions. Following graceful disconnection, the attacker reconnects with a short username combined with an unexpected db2java.zip version string. This specific sequence causes the server to remove a null terminator from memory locations, creating a condition where subsequent operations can overwrite adjacent stack memory. The vulnerability specifically relates to CWE-121 Stack-based Buffer Overflow, where insufficient boundary checking allows attackers to overwrite stack data structures and potentially control program execution flow through return address manipulation.
From an operational perspective, this vulnerability presents significant risk to database server environments as it allows remote code execution without requiring authentication for the initial connection phase. The attack requires minimal privileges to initiate but can result in complete system compromise when successful. The vulnerability affects the JDBC Applet Server component specifically, which serves as an interface for java-based database applications, making it particularly dangerous in environments where java applications interact with DB2 databases. The exploitation process demonstrates characteristics aligned with ATT&CK technique T1059.007 Command and Scripting Interpreter: Visual Basic, as the overflow can potentially enable attackers to execute arbitrary commands on the target system through the database server process.
The impact of this vulnerability extends beyond immediate code execution capabilities to encompass potential data breach scenarios and system compromise. Successful exploitation can lead to unauthorized access to sensitive database information, privilege escalation to database administrator levels, and potential lateral movement within network environments. Organizations using IBM DB2 8.1 with JDBC Applet Server functionality face significant exposure risk, particularly in environments where database servers are accessible from untrusted networks or where network segmentation is inadequate. The vulnerability's exploitation requires specific sequence of actions that make it somewhat more complex than typical buffer overflow scenarios, but the potential impact remains severe enough to warrant immediate attention and remediation.
Mitigation strategies for CVE-2005-4866 should focus on immediate patch application from IBM, which would address the underlying buffer overflow conditions in the JDBC Applet Server implementation. Network segmentation and access controls should be implemented to limit exposure of the affected database server components to untrusted networks. Additionally, monitoring for unusual connection patterns, particularly those involving long username sequences followed by short username reconnections, can help detect exploitation attempts. Organizations should also implement regular vulnerability assessments and penetration testing to identify similar conditions in other database server components. The fix addresses the core memory management issue by implementing proper bounds checking and null termination handling in the JDBC connection processing logic, preventing the overflow condition from occurring during normal operation sequences.