CVE-2003-0533 in Windows
Summary
by MITRE
Stack-based buffer overflow in certain Active Directory service functions in LSASRV.DLL of the Local Security Authority Subsystem Service (LSASS) in Microsoft Windows NT 4.0 SP6a, 2000 SP2 through SP4, XP SP1, Server 2003, NetMeeting, Windows 98, and Windows ME, allows remote attackers to execute arbitrary code via a packet that causes the DsRolerUpgradeDownlevelServer function to create long debug entries for the DCPROMO.LOG log file, as exploited by the Sasser worm.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 12/31/2024
The vulnerability described in CVE-2003-0533 represents a critical stack-based buffer overflow affecting the Local Security Authority Subsystem Service in multiple Microsoft Windows operating systems. This flaw specifically impacts LSASRV.DLL within the LSASS component, which handles core security functions including authentication and authorization processes. The vulnerability manifests when the DsRolerUpgradeDownlevelServer function processes incoming packets that trigger the creation of excessively long debug entries in the DCPROMO.LOG file, creating conditions where attacker-controlled data can overwrite adjacent memory locations on the stack.
The technical exploitation mechanism relies on the improper handling of debug logging within the Active Directory service functions, where the system fails to validate the length of incoming data before writing it to a fixed-size buffer. This particular flaw affects a wide range of Windows platforms including Windows NT 4.0 Service Pack 6a, Windows 2000 Service Packs 2 through 4, Windows XP Service Pack 1, Windows Server 2003, and older systems like Windows 98 and ME. The vulnerability's exploitation path demonstrates how insufficient input validation in system-level services can create remote code execution opportunities, as the Sasser worm specifically leveraged this weakness to propagate across networks without requiring user interaction or authentication.
The operational impact of this vulnerability extends beyond simple remote code execution to encompass complete system compromise and potential domain-wide infiltration. When exploited successfully, the buffer overflow allows attackers to execute arbitrary code with system-level privileges, potentially enabling them to establish persistent backdoors, escalate privileges, or deploy additional malware. The widespread affected platforms mean that organizations running any of these operating systems were vulnerable to exploitation, creating a massive attack surface that the Sasser worm effectively exploited to spread rapidly across networks. This vulnerability directly maps to CWE-121 Stack-based Buffer Overflow and aligns with ATT&CK techniques related to privilege escalation and remote code execution through service exploitation.
The exploitation of this vulnerability through the DCPROMO.LOG file mechanism highlights the dangerous combination of legacy system components and inadequate input validation in critical security services. The fact that this vulnerability was successfully weaponized by the Sasser worm demonstrates how seemingly minor flaws in system logging functions can create catastrophic security implications. Organizations with systems running the affected Windows versions were particularly vulnerable as the exploit required no authentication and could execute code remotely. Mitigation strategies included applying Microsoft security patches, implementing network segmentation to limit exposure, and disabling unnecessary Active Directory services. The vulnerability underscored the importance of proper input validation in system-level components and contributed to the evolution of more robust security practices in service-oriented architectures.