Microsoft fixing patch that can slow Windows XP

IDG News Service - Microsoft Corp. is revising a security patch for Windows XP systems with Service Pack 1 installed after customers complained that installing the patch slowed their systems down to a crawl.
Microsoft is working on a revised patch for Windows XP Service Pack 1 and will re-issue that patch when it has been completed and fully tested, the software maker said in a revised version of its security bulletin MS03-013, posted late yesterday.
Originally released on April 16, the security bulletin addressed a buffer overrun vulnerability in the Windows kernel, which manages core services for the operating system such as allocating processor time and memory, as well as error handling.
A flaw in the way the kernel passes error messages to a debugger could enable a malicious hacker to take any action on a vulnerable system such as deleting data, reconfiguring the device or modifying user accounts and privileges, Microsoft said in its advisory.
Soon after the patch was released, however, Windows XP users began complaining in online forums of performance problems that appeared after the patch was applied (see story).
Users reported that Windows XP could take as long as 10 seconds or more to start an application after installation of the patch. Removing the patch brought system speed back to normal, Windows XP users wrote in dozens of postings on several online discussion boards.
The company received a "small number" of complaints resulting from "special situations" involving the interaction of XP Service Pack 1 and third-party applications following the patch, according to Stephen Toulouse, security program manager at Microsoft's Security Response Center.
In updating its security bulletin, Microsoft acknowledged those problems but said customers running Windows XP Service Pack 1 should still consider applying the flawed patch as protection until a new version is released.
"Customers are encouraged to review this security bulletin [and] assess whether their particular environments demand that the patch should be applied immediately or whether their particular level of risk permits delaying deployment of the patch until it is revised and the performance problem corrected," the company said.
Microsoft is actively involved in finding a solution to the performance problems and investigating how the faulty patch made it through the company's patch review process, Toulouse said.
Microsoft said it will also publish a knowledge base article that describes what environmental factors produce slowdowns when combined with the XP patch and what can be done to reduce the impact of the slowdowns should they occur.
That article should be available within the next few days, according to Toulouse. However, he declined to estimate when an updated patch that resolves the performance issues will be available.