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 underneath energetic exploit now.
Six of the vulnerabilities that the corporate patched in its remaining month-to-month safety replace for the yr are listed as crucial. It assigned an vital severity ranking to 43 vulnerabilities and gave three flaws a average severity evaluation.
Microsoft’s replace consists of 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 Security Bug
The flaw that attackers are actively exploiting (CVE-2022-44698) just isn’t among the many extra crucial of the bugs for which Microsoft launched patches right this moment. The flaw offers attackers a method to bypass the Windows SmartScreen safety function for safeguarding customers in opposition to malicious recordsdata downloaded from the Internet.
“An attacker can craft a malicious file that will evade Mark of the Web (MOTW) defenses, leading to a restricted lack of integrity and availability of security measures resembling Protected View in Microsoft Office, 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 fame scanning and detection — specifically SmartScreen, which might usually pop as much as inform a person the file is probably not secure.”
At the identical time, customers mustn’t underestimate the risk and may patch the difficulty shortly, 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 underneath energetic exploit. The firm assessed the vulnerability (CVE-2022-44710) as being “Important” in severity and one that will enable an attacker to achieve system-level privileges if exploited. However, the corporate described the flaw as one which attackers are much less prone to exploit.
Vulnerabilities to Patch Now
Trend 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 person and trigger a sufferer to mistake an electronic mail message as if it got here from a legit person.
“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 risk consciousness Dustin Childs mentioned in a weblog put up. 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 enables an authenticated attacker to flee the PowerShell Remoting Session Configuration and run arbitrary instructions on an affected system, Microsoft mentioned.
The firm assessed the vulnerability as one thing that attackers are extra probably compromise, regardless that assault complexity itself is excessive. According to Childs, organizations ought to listen the vulnerability as a result of it’s the kind of flaw that attackers usually exploit when trying to “reside off the land” after gaining preliminary entry on a community.
“Definitely don’t ignore this patch,” Childs wrote.
And lastly, CVE-2022-44699 is one other safety bypass vulnerability — this time in Azure Network Watcher Agent — that, if exploited, may have an effect on a corporation’s capacity to seize logs wanted for incident response.
“There won’t be many enterprises counting on this instrument, however for these utilizing this [Azure Network Watcher] VM extension, this repair ought to be handled as crucial and deployed shortly,’ Childs mentioned.
Researchers with Cisco Talos recognized three different vulnerabilities as crucial and points that organizations want to handle instantly. One of them is CVE-2022-41127, an RCE vulnerability that impacts Microsoft Dynamics NAV and on-premises variations of Microsoft Dynamics 365 Business Central. A profitable exploit may enable an attacker to execute arbitrary code on servers operating Microsoft’s Dynamics NAV ERP software, Talos researchers mentioned in a weblog put up.
The different 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 Windows Secure Socket Tunneling Protocol (SSTP).
“Successful exploitation of those vulnerabilities requires an attacker to win a race situation however may allow an attacker to remotely execute code on RAS servers,” in response to Microsoft’s advisory.
Among the vulnerabilities that the SANS Internet Storm Center recognized as vital are (CVE-2022-41089), an RCE within the .NET Framework, and (CVE-2022-44690) in Microsoft SharePoint Server.
In a weblog put up, Mike Walters, vice chairman of vulnerability and risk analysis at Action1 Corp., additionally pointed to a Windows Print Spooler elevation of privilege vulnerability (CVE-2022-44678), as one other subject to look at.
“The newly resolved CVE-2022-44678 is almost certainly 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 threat from CVE-2022-44678 is similar: an attacker can get SYSTEM privileges after profitable exploitation — however solely domestically.”
A Confusing Bug Count
Interestingly, a number of distributors had completely different takes on the variety of vulnerabilities that Microsoft patched this month. ZDI, as an example, 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 all the way down to 52.
Johannes Ullrich, dean of analysis for the SANS Technology Institute, says the difficulty has to do with the alternative ways one can depend the vulnerabilities. Some, as an example, embody Chromium vulnerabilities of their depend whereas others don’t.
Others, like SANS, additionally embody safety advisories that typically accompany Microsoft updates as vulnerabilities. Microsoft additionally typically releases patches throughout the month, which it additionally consists of within the following Patch Tuesday replace, and a few researchers do not depend these.
“The patch depend can typically be complicated, because the Patch Tuesday cycle is technically November to December, so this will even embody patches that have been launched out of band earlier within the month, and may also embody updates from third social gathering distributors,” Breen says. “The most notable of those are patches from Google from Chromium, which is the bottom for Microsoft’s Edge browser.”
Breen says by his depend there are 74 vulnerabilities patched for the reason that final Patch Tuesday in November. This consists of 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 have 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.