Microsoft Squashes Zero-Day, Actively Exploited Bugs in Dec. Replace


Microsoft has launched fixes for 48 new vulnerabilities throughout its merchandise, together with one which attackers are actively exploiting and one other that has been publicly disclosed however just isn’t below energetic exploit now.

Six of the vulnerabilities that the corporate patched in its last month-to-month safety replace for the yr are listed as important. It assigned an essential severity ranking to 43 vulnerabilities and gave three flaws a average severity evaluation. 

Microsoft’s replace contains patches for out-of-band CVEs it addressed over the previous month, plus 23 vulnerabilities in Google’s Chromium browser expertise, on which Microsoft’s Edge browser is predicated.

Actively Exploited Safety Bug

The flaw that attackers are actively exploiting (CVE-2022-44698) just isn’t among the many extra important of the bugs for which Microsoft launched patches right this moment. The flaw offers attackers a solution to bypass the Home windows SmartScreen safety function for shielding customers towards malicious information downloaded from the Web. 

“An attacker can craft a malicious file that may evade Mark of the Internet (MOTW) defenses, leading to a restricted lack of integrity and availability of security measures resembling Protected View in Microsoft Workplace, which depend on MOTW tagging,” Microsoft mentioned.

CVE-2022-44698 presents solely a comparatively small threat for organizations, says Kevin Breen, director of cyber-threat analysis at Immersive Labs. “It needs to be utilized in partnership with an executable file or different malicious code like a doc or script file,” Breen says. “In these conditions, this CVE bypasses a few of Microsoft’s built-in repute scanning and detection — particularly SmartScreen, which might usually pop as much as inform a consumer the file might not be secure.” 

On the similar time, customers shouldn’t underestimate the menace and will patch the problem rapidly, Breen recommends.

Microsoft described one other flaw — an elevation of privilege subject within the DirectX Graphics kernel — as a publicly recognized zero-day however not below energetic exploit. The corporate assessed the vulnerability (CVE-2022-44710) as being “Vital” in severity and one that may permit an attacker to achieve system-level privileges if exploited. Nevertheless, the corporate described the flaw as one which attackers are much less more likely to exploit.

Vulnerabilities to Patch Now

Pattern Micro’s ZDI flagged three different vulnerabilities within the December Patch Tuesday safety replace as being important: CVE-2022-44713, CVE-2022-41076, and CVE-2022-44699.

CVE-2022-44713 is a spoofing vulnerability in Microsoft Outlook for Mac. The vulnerability permits an attacker to look as a trusted consumer and trigger a sufferer to mistake an electronic mail message as if it got here from a professional consumer. 

“We do not usually spotlight spoofing bugs, however anytime you are coping with a spoofing bug in an electronic mail consumer, you must take discover,” ZDI’s head of menace consciousness Dustin Childs mentioned in a weblog submit. The vulnerability may show particularly troublesome when mixed with the aforementioned SmartScreen MoTW bypass flaw that attackers are actively exploiting, he mentioned.

CVE-2022-41076 is a PowerShell distant code execution (RCE) vulnerability that permits an authenticated attacker to flee the PowerShell Remoting Session Configuration and run arbitrary instructions on an affected system, Microsoft mentioned. 

The corporate assessed the vulnerability as one thing that attackers are extra doubtless compromise, regardless that assault complexity itself is excessive. In accordance with Childs, organizations ought to listen the vulnerability as a result of it’s the kind of flaw that attackers usually exploit when seeking to “dwell off the land” after gaining preliminary entry on a community. 

“Undoubtedly don’t ignore this patch,” Childs wrote.

And at last, CVE-2022-44699 is one other safety bypass vulnerability — this time in Azure Community Watcher Agent that, if exploited, may have an effect on a company’s capacity to seize logs wanted for incident response. 

“There may not be many enterprises counting on this device, however for these utilizing this [Azure Network Watcher] VM extension, this repair must be handled as important and deployed rapidly,’ Childs mentioned.

Researchers with Cisco Talos recognized three different vulnerabilities as important and points that organizations want to deal with instantly. Considered one of them is CVE-2022-41127, an RCE vulnerability that impacts Microsoft Dynamics NAV and on-premises variations of Microsoft Dynamics 365 Enterprise Central. A profitable exploit may permit an attacker to execute arbitrary code on servers working Microsoft’s Dynamics NAV ERP utility, Talos researchers mentioned in a weblog submit. 

The opposite two vulnerabilities that the seller considers to be of excessive significance are CVE-2022-44670 and CVE-2022-44676, each of that are RCE flaws within the Home windows Safe Socket Tunneling Protocol (SSTP). 

“Profitable exploitation of those vulnerabilities requires an attacker to win a race situation however may allow an attacker to remotely execute code on RAS servers,” based on Microsoft’s advisory.

Among the many vulnerabilities that the SANS Web Storm Middle recognized as essential are (CVE-2022-41089), an RCE within the .NET Framework, and (CVE-2022-44690) in Microsoft SharePoint Server.

In a weblog submit, Mike Walters, vice chairman of vulnerability and menace analysis at Action1 Corp., additionally pointed to a Home windows Print Spooler elevation of privilege vulnerability (CVE-2022-44678), as one other subject to observe. 

“The newly resolved CVE-2022-44678 is most definitely to be exploited, which might be true as a result of Microsoft mounted one other zero-day vulnerability associated to Print Spooler final month,” Walters mentioned. “The chance from CVE-2022-44678 is identical: an attacker can get SYSTEM privileges after profitable exploitation however solely regionally.”

A Complicated Bug Rely

Apparently, a number of distributors had totally different takes on the variety of vulnerabilities that Microsoft patched this month. ZDI, as an illustration, assessed that Microsoft patched 52 vulnerabilities; Talos pegged the quantity at 48, SANS at 74, and Action1 initially had Microsoft patching 74, earlier than revising it right down to 52.

Johannes Ullrich, dean of analysis for the SANS Know-how Institute, says the problem has to do with the alternative ways one can rely the vulnerabilities. Some, as an illustration, embody Chromium vulnerabilities of their rely whereas others don’t. 

Others, like SANS, additionally embody safety advisories that typically accompany Microsoft updates as vulnerabilities. Microsoft additionally typically releases patches through the month, which it additionally contains within the following Patch Tuesday replace, and a few researchers do not rely these. 

“The patch rely can typically be complicated, because the Patch Tuesday cycle is technically November to December, so this may also embody patches that had been launched out of band earlier within the month, and may embody updates from third social gathering distributors,” Breen says. “Probably the most notable of those are patches from Google from Chromium, which is the bottom for Microsoft’s Edge browser.”
Breen says by his rely there are 74 vulnerabilities patched because the final Patch Tuesday in November. This contains 51 from Microsoft and 23 from Google for the Edge browser. 

“If we exclude each the out-of-band and Google Chromium [patches], 49 patches for vulnerabilities had been launched right this moment,” he says.

A Microsoft spokesman says the variety of new CVEs for which the corporate issued patches right this moment was 48.


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