This vulnerability is a zero-day and is being exploited in the wild. Of the 118 flaws for which patches were issued on Tuesday, 17 were rated as critical and 101 as important.
Security firm Tenable said in a blog post that Microsoft had also issued fixes for three security bypass flaws in a third-party driver that affected Secure Boot.
"These flaws were reported through the CERT Co-ordination Centre (CERT/CC). We have not included these flaws as part of our metrics for this month’s Patch Tuesday release because they are standalone security updates for third-party drivers," the company said.
"According to Microsoft, CVE-2022-34713 has been exploited in the wild as a zero-day and was publicly disclosed prior to a patch being available.
"The flaw is credited to Imre Rad, who first disclosed this type of vulnerability in MSDT back in January 2020. Microsoft originally declined to patch the flaw in 2020, but says that it qualified for a patch after a revision to its bug bar. CVE-2022-34713 appears to be a 'variant' of a flaw that researchers call DogWalk.
He said MSDT had received renewed focus since May, when it was discovered that attackers had used a zero-day in MSDT as part of malicious Word document files. The flaw, which was dubbed Follina by security researchers, was patched in June and is identified as CVE 2022-30190.
“With reports that CVE-2022-34713 has been exploited in the wild, it would appear that attackers are looking to take advantage of flaws within MSDT as these types of flaws are extremely valuable to launch spearphishing attacks," Narang added.
"A variety of threat actors leverage spear-phishing, from advanced persistent threat (APT) groups to ransomware affiliates. We’ve seen flaws like CVE-2017-11882, a remote code execution bug in Microsoft Office, continue to be exploited years after patches have been made available.
"For attackers, bugs that can be executed via malicious documents remain a valuable tool, so flaws like Follina and CVE-2022-34713 will continue to be used for months. Therefore, it is vital that organisations apply the available patches as soon as possible.”
Greg Wiseman, product manager at cyber security and compliance solutions and services provider Rapid7, said 141 separate vulnerabilities had been patched, but from a patching perspective the numbers were slightly less dire.
"Twenty CVEs affect the Chromium-based Edge browser and 34 affect Azure Site Recovery (up from 32 CVEs affecting that product last month)," he noted. "As usual, OS-level updates will address a lot of these, but note that some extra configuration is required to fully protect Exchange Server this month."
Wiseman said Microsoft had also patched several flaws affecting Remote Access Server.
"The most severe of these (CVE-2022-30133 and CVE-2022-35744) are related to Windows Point-to-Point Tunnelling Protocol, and could allow an RCE simply by sending a malicious connection request to a server," he explained.
"Seven CVEs affecting the Windows Secure Socket Tunnelling Protocol on RAS were also fixed this month: six RCEs and one denial of service. If you have RAS in your environment, but are unable to patch immediately, consider blocking traffic on port 1723 from your network."