Microsoft Patches Windows Privilege Escalation Flaws Exploited in Attacks

Microsoft has fixed over 70 vulnerabilities with its April 2019 Patch Tuesday updates, including two Windows zero-day flaws that allow an attacker to escalate privileges on a compromised system.

The actively exploited flaws, tracked as CVE-2019-0803 and CVE-2019-0859, appear similar — the security advisories published by Microsoft are nearly identical. They are both caused due to the way the Win32k component in Windows handles objects in memory and they both allow an authenticated attacker to execute arbitrary code in kernel mode.

All supported versions of Windows are impacted, but Microsoft is only aware of exploitation attempts against older versions of the operating system. It’s not uncommon for attacks to be neutralized by mitigations included in Windows 10.

Microsoft has credited researchers at Kaspersky Lab for reporting one of the flaws and Donghai Zhu of the Alibaba Cloud Intelligence Security Team for the second zero-day.

Details about these vulnerabilities and the attacks have yet to be released, but considering that the flaw reported by Kaspersky is similar to one patched by Microsoft last month, which threat actors tracked as FruityArmor and SandCat had exploited in targeted attacks, it’s possible that the same groups exploited these weaknesses as well.

Microsoft’s latest patches don’t address any security holes whose details were made public before the release of fixes.

However, they do resolve over a dozen critical remote code execution and privilege escalation vulnerabilities affecting Windows and the company’s web browsers.

Adobe’s Patch Tuesday updates for April 2019 fix over 40 vulnerabilities across eight products.

Related: Details of Actively Exploited Windows Flaw Made Public

Related: APT Group Uses Windows Zero-Day in Middle East Attacks