Microsoft OLE is reported prone to a remote buffer overflow vulnerability. This issue arises because the application fails to perform boundary checks before copying user-supplied data to sensitive process buffers. A remote attacker may leverage this vulnerability to execute arbitrary code on a vulnerable computer. If a vulnerable user opens a malicious file through any application that supports OLE, the attacker-supplied arbitrary code may be executed in the context of the user. Reportedly, user interaction is required to exploit this condition in Microsoft Windows 2000, Windows XP, and Windows Server 2003. An anonymous remote user can exploit this issue in various versions of Microsoft Exchange Server because Exchange Server uses the affected Windows OLE component. A successful attack can allow the attacker to gain SYSTEM privileges as the Microsoft Exchange Server runs with elevated privileges. Affected Microsoft Exchange Server versions include Microsoft Exchange 2000 Server, Microsoft Exchange Server 2003, Microsoft Exchange Server 5.0, and Microsoft Exchange Server 5.5. Other applications that use the affected Windows OLE component include Microsoft Office XP Service Pack 3, Microsoft Office XP Service Pack 2, Microsoft Office 2003 Service Pack 1, and Microsoft Office 2003.
Block external access at the network boundary, unless external parties require service.
Access to affected computers should be filtered at the network boundary. Restricting access to only trusted computers and networks might greatly reduce the likelihood of exploitation.
Deploy network intrusion detection systems to monitor network traffic for malicious activity.
Deploy network intrusion detection systems to monitor all network traffic for signs of suspicious or anomalous activity. This may aid in detecting attempts to exploit latent vulnerabilities or in detecting malicious activity that occurs as a result of successful exploitation.
Do not accept or execute files from untrusted or unknown sources.
Users should not accept files from untrusted or unknown sources, as they may be malicious in nature. Avoid opening email attachments from unknown or questionable sources.
Do not follow links provided by unknown or untrusted sources.
Users should avoid Web sites of questionable integrity and not follow links supplied by unknown or untrusted sources.
Run all software as a nonprivileged user with minimal access rights.
Users should perform all non-administrative tasks as an unprivileged user with minimal access rights. This will limit the impact of latent vulnerabilities.
Microsoft has released updates to address this vulnerability on supported platforms. Nortel Networks has released security advisory 2005005514 acknowledging this issue. Please the referenced advisory for further information.