Microsoft Patch Slows Some Systems
Programmers keep working on SSL flaw, since fix causes slowdowns, shutdowns on some Windows 2000 PCs.
Paul Roberts, IDG News Service
A recent Windows patch is causing some Windows 2000 machines to stop responding after it is installed, Microsoft has acknowledged.
Some systems that use the security update released earlier in April, MS04-011, stop responding when they start up. They may also prevent users from logging on to Windows, or bog down once running, Microsoft says in an article posted Wednesday in its Knowledge Base online help database.
Fixes SSL, PCT Flaws
The security patch fixes a number of holes in Windows, including problems with the Windows implementation of Secure Sockets Layer (SSL). The protocol is frequently used to secure communications between servers and clients on public networks and the Internet.
Included in the patch is a fix for a buffer overrun in the Private Communications Transport (PCT) protocol, which is part of Microsoft's SSL library. PCT is a protocol in that library that was developed by Microsoft and Visa International to conduct encrypted communication on the Internet, Microsoft says.
Shortly after Microsoft released that patch, malicious code that could be used to trigger the PCT buffer overflow and compromise Windows systems appeared on the Internet. In recent days, security companies warned of widespread attacks that use the exploit code, though the code hasn't yet been tied to a virus or Internet worm.
An attacker who could exploit the PCT hole could take complete control of affected systems. They could install programs; view, modify, or delete data; or change user access to the system, Microsoft says.
Since releasing the patch, Microsoft has encouraged customers to apply it as soon as possible. However, now it appears that the patch comes with its own problems.
Ongoing Research
Microsoft's Knowledge Base article says a software change in the patch causes Windows 2000 systems to repeatedly try to load drivers that cannot load successfully, causing the hangups.
The company lists three software drivers that, if installed, make Windows 2000 systems susceptible to the slowdowns. The Knowledge Base article also describes specific problems and a workaround procedure for Windows systems that have a Nortel Networks virtual private network client installed.
However, the company acknowledges the slowdowns may occur with other combinations of drivers and services that don't load successfully. Microsoft representatives say they are researching the slowdown problem and will release more information when it is available.
Faulty patches are a frequent source of concern for Microsoft, which encourages its customers to install security patches as soon as possible to protect Windows systems from attack. Network administrators, on the other hand, are often reluctant to move quickly with software updates, fearing that, once installed, they will break critical systems.
