Fixing a vulnerability is NOT supposed to make it go from BAD to WORSE - Security researcher found that Microsoft's security fixes to Windows 7 PCs for the Meltdown flaw—which could allow attackers to read kernel memory at a speed of 120 KBps—is now allowing attackers to read the same kernel memory at a speed of Gbps, making the issue even worse on Windows 7 PCs and Server 2008 R2 boxes.

The discovery is the latest issue surrounding Meltdown and Spectre patches that were sometimes found incomplete and sometimes broken, making problems such as spontaneous reboots and other 'unpredictable' system behavior on affected PCs.

All attackers have to do is to write their own Page Table Entries (PTEs) into the page tables in order to access arbitrary physical memory.


https://thehackernews.com/2018/03/microsofts-meltdown-vulnerability.html