Critical Security Fixes on Tap for Windows, Outlook

Patch Tuesday, with four critical bulletins, also will bring fixes to Windows Mail, Internet Explorer and Word.

Microsoft will be putting out seven security advisories on Patch Tuesday, Oct. 9, with four critical bulletins out for Windows, Outlook Express, Windows Mail, Internet Explorer and Word.

Three bulletins are also on tap that target "important" flaws in Windows, SharePoint Services and Office SharePoint Server, according to a bulletin sent out on Symantecs DeepSite Alert Services

That about does it for details released in the advance notification from Microsoft, of Redmond, Wash.

eEye Digital Securitys Zero-Day Tracker gives some further hints as to what might be in store, however. One medium-risk vulnerability in Windows XP that the security firm is currently tracking can lead to an Internet connection-sharing DoS (denial-of-service) situation and remote shutdown of Windows Firewall from a LAN.

That flaw has seen 341 days of exposure. It allows a LAN-side attacker to send a maliciously rigged DNS request to a vulnerable host to shut down the ICS service, which also includes the Windows firewall service. This problem wont lead to remote code execution, but it could lead to further exploitation after the firewall is kicked offline, notes eEye, of Aliso Viejo, Calif. The security firm Retina Network Security Scanner detected the vulnerability. But apart from that, mitigation amounts to disabling the ICS service or blocking udp/53 on the host running ICS, eEye said.

Proof-of-concept code has been published on the Milw0rm exploit list for the vulnerability, which is identified as CVE-2006-5614.

The only other open Microsoft vulnerability eEye is now tracking is a low-risk Windows flaw that can lead to RPC (remote procedure call) memory exhaustion.

The RPC flaw has been floating around since Nov. 2005—a total of 687 days. Three proof-of-concept code sets have been published on the vulnerability, which can allow an attacker to supply the size of an output buffer. If that occurs, RPC allocates the buffer and initializes it to zeroes, causing the entire memory range to become committed.

"For huge output buffers, the target service [which is given all the virtual memory it wants, due to its privileges] will cause virtual memory exhaustion, in the worst cases resulting in page file thrashing, a low virtual memory message and general system unresponsiveness," eEye said.

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