She released a Proof-of-concept (PoC) exploit in GitHub and it was a fourth Windows zero-day bug that she discovered and leaked last year.
Windows Zero-day Flaw
New Zero-day exploit given by the researcher via Github allows overwriting a ‘
Bleeping computer states that “the exploit she wrote works with some limitations and may not have the expected effect on some CPUs. For instance, she could not reproduce the bug on a machine with one CPU core.”
Further analyses were done by the vulnerability analyst from CERT/CC, and he reports that the overwrite does not occur consistently.
He added it in his Tweet, This latest 0day from SandboxEscaper requires a lot of patience to reproduce. And beyond that, it only *sometimes* overwrites the target file with data influenced by the attacker. Usually it’s unrelated WER data.
‘Since the bug exploit the ‘Pci.sys’, it may cause DDOS even for the users who have not an admin privilege and also it leads to disabling the 3 rd part Anti-Virus Software.
Usually, she didn’t report the bug to Microsoft but this time she reported to
Microsoft Security Response Center(MSRC) which is also she quoted in her tweet, unfortunately, Twitter Suspended her account.
This is a second Zeroday bug within a month of December 2018 and the first flow affected the ReadFile.exe, A windows functions that help to reads data from the specified file or input/output (I/O) device.