Microsoft’s Patch Tuesday updates for December 2018 address nearly 40 vulnerabilities, including a zero-day flaw affecting the Windows kernel.
The actively exploited vulnerability, tracked as CVE-2018-8611, has been described by Microsoft as a privilege escalation issue related to the failure of the Windows kernel to properly handle objects in memory.
“An attacker who successfully exploited this vulnerability could run arbitrary code in kernel mode. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights,” Microsoft said in its advisory.
Exploitation of the vulnerability requires access to the targeted system. The security hole impacts all supported versions of Windows.
Microsoft has credited Kaspersky Lab researchers for reporting the vulnerability. The cybersecurity firm is expected to publish a report detailing the flaw and the attacks exploiting it.
This is the third month in a row Microsoft patches a Windows zero-day discovered by experts at Kaspersky. In October, the tech giant patched CVE-2018-8453, a privilege escalation exploited by a threat group known as FruityArmor. Last month, it fixed CVE-2018-8589, which had been used in limited attacks aimed at entities in the Middle East.
Microsoft’s latest round of patches also resolves an “important” denial-of-service (DoS) flaw in .NET that has been publicly disclosed.
“The vulnerability can be exploited remotely without authentication by issuing a specially crafted request to the vulnerable application,” explained Chris Goettl, director of product management and security at Ivanti. “The vulnerability is rated as Important likely due to complexity to exploit, but it has been publicly disclosed meaning enough information has been revealed to the public to give a threat actor a head start on creating an exploit to take advantage of the vulnerability. Public disclosures increase the odds a vulnerability will be exploited.”
The list of critical vulnerabilities patched this month includes nine remote code execution flaws impacting the .NET framework, the Edge and Internet Explorer web browsers, Windows DNS servers, and the text-to-speech feature.
Adobe this month patched 87 vulnerabilities affecting the Windows and macOS versions of its Acrobat products.