March 28, 2023

Microsoft on Tuesday launched updates to quash not less than 74 safety bugs in its Home windows working methods and software program. Two of these flaws are already being actively attacked, together with an particularly extreme weak spot in Microsoft Outlook that may be exploited with none consumer interplay.

The Outlook vulnerability (CVE-2023-23397) impacts all variations of Microsoft Outlook from 2013 to the most recent. Microsoft mentioned it has seen proof that attackers are exploiting this flaw, which might be completed with none consumer interplay by sending a booby-trapped e mail that triggers mechanically when retrieved by the e-mail server — earlier than the e-mail is even considered within the Preview Pane.

Whereas CVE-2023-23397 is labeled as an “Elevation of Privilege” vulnerability, that label doesn’t precisely mirror its severity, mentioned Kevin Breen, director of cyber risk analysis at Immersive Labs.

Referred to as an NTLM relay assault, it permits an attacker to get somebody’s NTLM hash [Windows account password] and use it in an assault generally known as “Pass The Hash.”

“The vulnerability successfully lets the attacker authenticate as a trusted particular person with out having to know the individual’s password,” Breen mentioned. “That is on par with an attacker having a sound password with entry to a company’s methods.”

Safety agency Rapid7 factors out that this bug impacts self-hosted variations of Outlook like Microsoft 365 Apps for Enterprise, however Microsoft-hosted on-line providers like Microsoft 365 are not weak.

The opposite zero-day flaw being actively exploited within the wild — CVE-2023-24800 — is a “Safety Characteristic Bypass” in Home windows SmartScreen, a part of Microsoft’s slate of endpoint safety instruments.

Patch administration vendor Action1 notes that the exploit for this bug is low in complexity and requires no particular privileges. However it does require some consumer interplay, and might’t be used to realize entry to personal info or privileges. Nevertheless, the flaw can enable different malicious code to run with out being detected by SmartScreen popularity checks.

Dustin Childs, head of risk consciousness at Pattern Micro’s Zero Day Initiative, mentioned CVE-2023-24800 permits attackers to create recordsdata that might bypass Mark of the Internet (MOTW) defenses.

“Protecting measures like SmartScreen and Protected View in Microsoft Workplace depend on MOTW, so bypassing these makes it simpler for risk actors to unfold malware by way of crafted paperwork and different contaminated recordsdata that might in any other case be stopped by SmartScreen,” Childs mentioned.

Seven different vulnerabilities Microsoft patched this week earned its most-dire “crucial” severity label, which means the updates tackle safety holes that could possibly be exploited to provide the attacker full, distant management over a Home windows host with little or no interplay from the consumer.

Additionally this week, Adobe launched eight patches addressing a whopping 105 safety holes throughout a wide range of merchandise, together with Adobe Photoshop, Chilly Fusion, Expertise Supervisor, Dimension, Commerce, Magento, Substance 3D Stager, Cloud Desktop Application, and Illustrator.

For a extra granular rundown on the updates launched immediately, see the SANS Internet Storm Center roundup. If immediately’s updates trigger any stability or usability points in Home windows, will seemingly have the lowdown on that.

Please think about backing up your information and/or imaging your system earlier than making use of any updates. And be happy to pontificate within the feedback when you expertise any issues on account of these patches.