Microsoft Windows does not adequately validate IP options, allowing an unauthenticated, remote attacker to execute arbitrary code or cause a denial of service. An attacker could take complete control of a vulnerable system.
Several versions of the Microsoft Windows IP stack are vulnerable to specially crafted packets that contain malformed IP options. When processing such a packet, a vulnerable IP stack may initially validate the options and pass them to code that uses the options data in ways that corrupt memory. Routers may drop packets with malformed IP options, so an attacker may need to be able to send packets from the same IP subnet as the target system. IP tunnels (VPNs, GRE) may deliver malformed packets through a router that would otherwise drop them.
An unauthenticated, remote attacker could execute arbitrary code or cause a denial of service. Since the IP stack is implemented as a kernel driver, an attacker who successfully executes arbitrary code could gain complete control of a vulnerable system. Kernel memory corruption caused by an attack could cause a vulnerable system to crash and possibly reboot.
Apply a patch
Apply the appropriate patch (893066) referenced by Microsoft Security Bulletin MS05-019. Microsoft Knowledge Base Article 893066 describes several issues related to the patch, including possible degraded network performance (890345).
Filter packets with malformed IP options
Filter packets with malformed IP options at network borders.
Vendor| Status| Date Notified| Date Updated
Microsoft Corporation| | -| 12 Apr 2005
If you are a vendor and your product is affected, let us know.
Group | Score | Vector
Base | N/A | N/A
Temporal | N/A | N/A
Environmental | N/A | N/A
This vulnerability was reported by Microsoft, who credits ISS X-Force.
This document was written by Art Manion.