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A team of cybersecurity researchers yesterday revealed details of a new side-channel attack on dynamic random-access memory (DRAM) that could allow malicious programs installed on a modern system to read sensitive memory data from other processes running on the same hardware.

Dubbed RAMBleed and identified as CVE-2019-0174, the new attack is based on a well-known class of DRAM side channel attack called Rowhammer, various variants [GLitchRAMpageThrowhammerNethammerDrammer] of which have been demonstrated by researchers in recent years.

Known since 2012, Rowhammer bug is a hardware reliability issue that was found in the new generation of DRAM chips.

It turned out that repeatedly and rapidly accessing (hammering) a row of memory can cause bit flips in adjacent rows, i.e., changing their bit values from 0 to 1 or vice-versa.

In the following years, researchers also demonstrated successful exploits to achieve privilege escalation on the vulnerable computers by flipping (writing) bits in the victim’s memory.

Discovered by a team of researchers from the University of Michigan, Graz University of Technology and the University of Adelaide, the new RAMBleed also relies on the bit-flip mechanism; but instead of writing data in the adjacent rows, this attack allows attackers to read the information in protected memory belonging to other programs and users.

images from Hacker News