A zero-day vulnerability is basically an unknown software bug. Upon identification and discovery, it allows attackers to conduct malicious activities in the shadows, resulting in unexpected and destructive consequences.
While analysing the CVE-2021-1732 exploit, Kaspersky experts found another zero-day exploit and reported it to Microsoft in February. After confirmation that it is indeed a zero-day, it received the designation CVE-2021-28310.
According to the researchers, this exploit is used in the wild, potentially by several threat actors. It is an escalation of privilege (EoP) exploit, found in Desktop Window Manager, allowing the attackers to execute arbitrary code on a victim’s machine.
It is likely that the exploit is used together with other browser exploits to escape sandboxes or obtain system privileges for further access.
Kaspersky’s initial investigation has not revealed the full infection chain, so it is yet not known whether the exploit is used with another zero-day or coupled with known, patched vulnerabilities.
“The exploit was initially identified by our advanced exploit prevention technology and related detection records. In fact, over the past few years, we have built a multitude of exploit protection technologies into our products that have detected several zero-days, proving their effectiveness time and time again. We will continue to improve defenses for our users by enhancing our technologies and working with third-party vendors to patch vulnerabilities, making the internet more secure for everyone,” comments Boris Larin, security expert at Kaspersky.
More information about BITTER APT and IOCs are available to customers of the Kaspersky Intelligence Reporting service. Contact: firstname.lastname@example.org.
A patch for the elevation of privilege vulnerability CVE-2021-28310 was released on April 13th, 2021.
Kaspersky products detect this exploit with the following verdicts:
For further details on the new exploit, see the full report on Securelist.
To take a closer look at the technologies that detected this and other zero-days in Microsoft Windows, a recorded Kaspersky webinar is available to view on demand.