Buzz
Swedish security expert, Ulf Frisk, discovered that the Meltdown patch unveils a more extensive security hole on Windows 7 earlier this month while using PCILeech, a device he created for executing DMA (Direct Memory Access) attacks and compromising the protected operating system memory.
The Security Patch for Meltdown Exposes a Greater Security Vulnerability on Windows 7
Meltdown Patch Grants User Access to Kernel Memory
Frisk reveals that Microsoft's Meltdown fix (CVE-2017-5754), released on Patch Tuesday in January, inadvertently reverses control over access to kernel memory. According to Frisk's explanation:
'In essence, the permission allowing User/Supervisor is set to User in the self-referencing entry of PML4. This is for page tables available in user-mode code in processes. Normal page tables can then be accessed by the kernel.'
'PML4 is the foundation of the 4-level hierarchical page table in the Memory Management Unit (MMU) block within the CPU, used to translate virtual addresses of a process into physical memory addresses in RAM.'
Microsoft Quietly Releases Patch Tuesday March Update
According to Frisk, this issue only affects Windows 7 and Windows Server 2008 64-bit versions.
Users of Windows 7 and Windows Server 2008 R2 are advised to install the Patch Tuesday updates for January and March released by Microsoft to fix the issues, or you can follow the Windows 7 update guide on Mytour.
Windows 10 and Windows 8.1 systems will not be affected. The vulnerability discovered by Frisk requires physical access for exploitation.
Box, the storage service, has been around for quite some time. Despite the efforts of its developers to bring the Box app to various platforms for computers and phones to make it more widespread, it seems that saying farewell to Windows Phone and Windows 10 is inevitable as the developers are not very enthusiastic about UWP.
