Pierluigi Paganini October 24, 2018

The security researcher SandboxEscaper has released the proof-of-concept exploit code for a new Windows zero-day, Windows users are now exposed to attacks.

The security researcher using the Twitter handle @SandboxEscaper is back and has released the proof-of-concept exploit code for a new Windows zero-day vulnerability.

At the end of August, the same researcher disclosed the details of zero-day privilege escalation vulnerability affecting the Microsoft’s Windows Windows Task Scheduler that could be exploited by a local attacker or malicious program to obtain system privileges on the vulnerable system.

Now SandboxEscaper published a tweet containing a link to a Github page hosting a proof-of-concept (PoC) exploit for a privilege escalation vulnerability affecting Microsoft Data Sharing (dssvc.dll).

The Data Sharing Service is a local service that runs as LocalSystem account with extensive privileges, it provides data brokering between applications.

https://twitter.com/SandboxEscaper/status/1054744201244692485

Security experts that the way SandboxEscaper’ disclosed the flaw has left all Windows users vulnerable to the cyber attacks, at least since Microsoft will not address it. A new round of security updates in scheduled for November 13, 2018.

The vulnerability could be exploited by an attacker with low privileges to elevate them on the vulnerable system. The expert shared the PoC exploit code (deletebug.exe) to delete critical system files, an operation that requests admin level privileges.ù

“Not the same bug I posted a while back, this doesn’t write garbage to files but actually deletes them.. meaning you can delete application dll’s and hope they go look for them in user write-able locations. Or delete stuff used by system services c:\windows\temp and hijack them,” SandboxEscaper explained.

Security experts noticed that the flaw only affects Windows 10 and recent versions of Windows Server editions because older versions of the Microsoft operating systems don’t implement the Microsoft Data Sharing service.

The popular researcher Will Dormann successfully tested the PoC exploit on fully-patched Windows 10 system” running an OS version that included the October 2018 security updates, Server 2016 and Server 2019.

Experts fear that the release of the PoC could help attackers in actively exploiting the flaw in the wild.

Pierluigi Paganini

(Security Affairs – Windows zero-day, hacking)

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