The software giant addresses a list of vulnerabilities present in its Windows and Office programs, with six patches released to fix critical issues in both products.
Microsoft released 10 individual security patches on Oct. 10, addressing a handful of critical problems in Office programs along with several equally serious issues in its Windows operating system.
In all, the software maker issued patches for six critical flaws, one important problem, two moderate glitches and one low-priority issue.
The "critical" designation represents the highest severity rating for product security bulletins issued by Microsoft.
As expected, among the security bulletins was a fix meant to address a vulnerability in Windows so-called shell code which could allow for remote attack execution if exploited.
The flaw, labeled by security researcher as "SetSlice" and first discovered in the Internet Explorer browser, has already become an attack vector for hackers, some of whom have begun distribution of Trojan and rootkit viruses meant to take advantage of the vulnerability.
The Windows Shell vulnerability was first released during security researcher HD Moores Month of Browser Bugs project in July, and some of the attacks targeting the vulnerability have been launched by a known cyber-crime organization operating out of Russia, according to virus researchers.
Redmond, Wash.-based Microsoft said that the Windows Shell issue is related to improper validation of input parameters when invoked by the softwares WebViewFolderIcon ActiveX control.
The company said the vulnerability could allow for remote code execution if a user visited a specially crafted Web site or views a specially crafted e-mail message designed to attack the flaw.
An attacker could also exploit the vulnerability by hosting a Web site that contained a URL that was designed to exploit the issue, and subsequently take complete control of an affected system.
Among the other security bulletins offered by Microsoft is a patch for a set of vulnerabilities in the PowerPoint presentation application in Office which could also lead to remote code execution if exploited.
The company identified four individual issues in the program, including a malformed object pointer issue, a malformed data record flaw, a malformed record memory corruption glitch and a malformed record problem.
Each of the issues affects all of the versions of the program since the Office 2000 iteration of the product, save the malformed object pointer issue, which does not affect PowerPoint 2000, PowerPoint 2003 and PowerPoint 2004, but does impact the PowerPoint 2003 release.
To read more about PowerPoint flaws, click here.
In each of the PowerPoint issues, Microsoft reported that users with administrative user rights could be attacked by someone who successfully exploited this vulnerability, allowing the outsider to take complete control of an affected system.
A successful attacker could then install programs, or view, change and delete data, as well as create new accounts with full user rights.
Users whose accounts are configured to have fewer user rights on the system could be less affected than users who operate with administrative user rights, the company said.
In another critical bulletin, Microsoft said it has addressed a set of four problems in its Excel spreadsheet program which could lead to remote code execution.
The company reported that the update, which replaces an earlier Excel security patch, addresses several newly discovered vulnerabilities that could allow users logged on with administrative permission to be attacked. The issue affects all iterations of Excel going back to the 2000 release.
Another cumulative critical bulletin promises to address a series of issues in Microsoft Word, specifically four individual vulnerabilities relating to the programs record and file subsystems.
In each case users logged in with administrative rights could be attacked by outsiders using specially crafted code or Web pages and have their machines taken over completely.
The problems affect each version of Excel released since the 2000 generation of the product, but the issue merits only Microsofts less-severe "important" security rating in iterations other than Excel 2000.
An additional set of four individual vulnerabilities is addressed in another Microsoft patch for Office, including problems related to improper memory access, malformed record charts, malformed memory corruption and the products smart tag parsing feature.
Microsoft said that the problems, which could all allow for remote code execution attacks against users logged in with administrative permissions, are critical for Office 2000, and merely important for subsequent versions of the productivity suite.
The final critical bulletin is meant to address two separate vulnerabilities in Microsofts XML Core Services that could allow for outside attack.
One of the flaws, if exploited by an attacker, could allow for information disclosure, and ranks as important across all versions of Windows since the 2000 iteration of the product.
The other, which involves a buffer overrun vulnerability, could allow for remote code execution and is rated as critical across all versions of Windows since the 2000 generation.
In its lone "important" security bulletin, Microsoft addressed a pair of issues in Windows server service capabilities.
The problem could be used by an attacker to cause denial-of-service attacks on machines running the program, and affects all versions of the product going back to Windows 2000.
The two moderate security issues tackled in the patch distribution involve a Windows vulnerability related to the programs ASP.NET 2.0 code, which could allow for information disclosure if exploited, and an issue in the products Object Packager that could allow remote code execution.
The Object Packager issue affects only the Windows XP generation of the product, while the ASP.NET 2.0 flaw applies only to Microsofts .NET Framework 2.0.
The only security bulletin rated by Microsoft as low revolves around a set of three vulnerabilities found in the TCP/IP IPv6 code in Windows XP products, and could allow for denial of service attacks if exploited.
Check out eWEEK.coms for the latest security news, reviews and analysis. And for insights on security coverage around the Web, take a look at eWEEK.com Security Center Editor Larry Seltzers Weblog.