Microsoft Releases Fix for Zero-Day Flaw in July 2022 Security Patch Rollout

Jul 13, 2022Ravie Lakshmanan

Microsoft released its monthly round of Patch Tuesday updates to address 84 new security flaws spanning multiple product categories, counting a zero-day vulnerability that's under active attack in the wild.

Of the 84 shortcomings, four are rated Critical, and 80 are rated Important in severity. Also separately resolved by the tech giant are two other bugs in the Chromium-based Edge browser, one of which plugs another zero-day flaw that Google disclosed as being actively exploited in real-world attacks.

Top of the list of this month's updates is CVE-2022-22047 (CVSS score: 7.8), a case of privilege escalation in the Windows Client Server Runtime Subsystem (CSRSS) that could be abused by an attacker to gain SYSTEM permissions.

"With this level of access, the attackers are able to disable local services such as Endpoint Detection and Security tools," Kev Breen, director of cyber threat research at Immersive Labs, told The Hacker News. "With SYSTEM access they can also deploy tools like Mimikatz which can be used to recover even more admin and domain level accounts, spreading the threat quickly."

Very little is known about the nature and scale of the attacks other than an "Exploitation Detected" assessment from Microsoft. The company's Threat Intelligence Center (MSTIC) and Security Response Center (MSRC) have been credited with reporting the flaw.

Besides CVE-2022-22047, two more elevation of privilege flaws have been fixed in the same component — CVE-2022-22026 (CVSS score: 8.8) and CVE-2022-22049 (CVSS score: 7.8) — that were reported by Google Project Zero researcher Sergei Glazunov.

"A locally authenticated attacker could send specially crafted data to the local CSRSS service to elevate their privileges from AppContainer to SYSTEM," Microsoft said in an advisory for CVE-2022-22026.

"Because the AppContainer environment is considered a defensible security boundary, any process that is able to bypass the boundary is considered a change in Scope. The attacker could then execute code or access resources at a higher integrity level than that of the AppContainer execution environment."

Also remediated by Microsoft include a number of remote code execution bugs in Windows Network File System (CVE-2022-22029 and CVE-2022-22039), Windows Graphics (CVE-2022-30221), Remote Procedure Call Runtime (CVE-2022-22038), and Windows Shell (CVE-2022-30222).

The update further stands out for patching as many as 32 issues in the Azure Site Recovery business continuity service. Two of these flaws are related to remote code execution and the remaining 30 concern privilege escalation.

"Successful exploitation [...] requires an attacker to compromise admin credentials to one of the VMs associated with the configuration server," the company said, adding the flaws do not "allow disclosure of any confidential information, but could allow an attacker to modify data that could result in the service being unavailable."

On top of that, Microsoft's July update also contains fixes for four privilege escalation vulnerabilities in the Windows Print Spooler module (CVE-2022-22022, CVE-2022-22041, CVE-2022-30206, and CVE-2022-30226) after a brief respite in June 2022, underscoring what appears to be a never-ending stream of flaws plaguing the technology.

Rounding off the Patch Tuesday updates are two notable fixes for tampering vulnerabilities in the Windows Server Service (CVE-2022-30216) and Microsoft Defender for Endpoint (CVE-2022-33637) and three denial-of-service (DoS) flaws in Internet Information Services (CVE-2022-22025 and CVE-2022-22040) and Security Account Manager (CVE-2022-30208).

Software Patches from Other Vendors

In addition to Microsoft, security updates have also been released by other vendors since the start of the month to rectify several vulnerabilities, including —