News

Microsoft Reports Critical Vulnerability in Windows 2000, XP

Microsoft Corp. reported a critical vulnerability in Windows 2000 and Windows XP on Thursday. The flaw results from an unchecked buffer in Microsoft's Point-to-Point Tunneling Protocol (PPTP) implementation in the two operating systems. An attacker could exploit the flaw to mount a denial of service attack.

The bulletin was one of three security bulletins released by Microsoft's security team on Thursday morning. The other newly patched vulnerabilities involve Internet Information Server and Windows 2000.

PPTP is a Virtual Private Networking technology natively supported in Windows 2000 and Windows XP. According to the bulletin, the unchecked buffer exists in a section of code that processes the control data used to establish, maintain and tear down PPTP connections.

An attacker would exploit the flaw by sending specially malformed PPTP control data to a server or workstation acting as a server. The attack could corrupt kernel memory and cause the system to fail. Rebooting restores normal operation. PPTP is not enabled by default on any Windows system so servers have to be configured to offer PPTP services to be vulnerable.

In a separate bulletin, four less serious vulnerabilities in IIS got patches. The most serious of the vulnerabilities makes it possible for applications on a server to gain system-level privileges. The patch for the flaws is cumulative, including all IIS-related fixes since Windows NT 4.0 Service Pack 6a.

The other security vulnerability, rated "moderate," by Microsoft is that default permissions in Windows 2000 could allow a Trojan horse program. Microsoft says the systems most at risk from this vulnerability is a workstation shared by several users. The attacker would need to be able to log on locally to load the Trojan horse.

So far this year, Microsoft has distributed 64 security bulletins for its products.

Click here to view Microsoft's new security bulletins:

  • Cumulative patch for IIS vulnerabilities,
  • Critical PPTP implementation flaw,
  • Trojan horse program execution.

  • About the Author

    Scott Bekker is editor in chief of Redmond Channel Partner magazine.

    Featured

    • Microsoft Offers Endpoint Configuration Manager Advice for Keeping Remote Clients Patched

      Microsoft this week offered advice for organizations using Microsoft Endpoint Configuration Manager with remote Windows systems that need to get patched, and it also announced Update 2002.

    • Azure Edge Zones Hit Preview

      Azure Edge Zones, a new edge computing technology from Microsoft designed to enable new scenarios for developers and partners, emerged as a preview release this week.

    • Microsoft Shifts 2020 Events To Be Online Only

      Microsoft is shifting its big events this year to be online only, including Ignite 2020.

    • Microsoft Browser Support for TLS 1.0 and 1.1 Ending 2H 2020

      Microsoft announced on Tuesday that its plans to drop support for Transport Layer Security (TLS) protocols 1.0 and 1.1 in its browsers will get delayed by a few months until the second half of this year.

    comments powered by Disqus

    Office 365 Watch

    Sign up for our newsletter.

    Terms and Privacy Policy consent

    I agree to this site's Privacy Policy.