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Security researchers have managed to launch an attack on Linux computers by targeting a physical weakness in some types of DDR memory chips, Ars Technica reports.
The technique was published on Google’s Project Zero website by Mark Seaborn, and elevates the system rights of untrusted users of Intel compatible computers running Linux by reversing bits of data stored in DDR3 chip modules.
It builds on research from last year that revealed ‘bit flipping’ (repeatedly accessing small regions of memory) could allow an attacker to change the value of content stored in computer memory. The researchers found that this could then be used to change administrator privileges on a target PC.
Tech Radar reports that the exploit affects newer versions of DDR3 memory, which can are open to the vulnerability “thanks to the shrinking size of silicon that makes it easier to trigger electronic interaction between neighboring cells.”
While it sounds like a particularly concerning attack, given it targets hardware rather than software, the nature of the hack means it is quite difficult to pull off in the real world. For starters, it is only known to work locally, meaning remote attacks are out.
Secondly, the bitflipping technique used by researchers only works on memory without error correction – a fairly common feature. This may explain why 14 of the 29 laptops sampled held strong against the attack.
Despite this, Seaborn concluded the research with a plea to memory hardware manufacturers to treat the discovery in the same way software vendors would, on being informed of a vulnerability: “Though the industry is less accustomed to hardware bugs than to software bugs, we would like to encourage hardware vendors to take the same approach: thoroughly analyse the security impact of ‘reliability’ issues, provide explanations of impact, offer mitigation strategies and — when possible — supply firmware or BIOS updates,” he wrote.
“Such discussion will lead to more secure hardware, which will benefit all users.”
The researchers did not mention any specific models of computer or memory in the post, but in a written statement to Wired, a Google spokesperson claimed that the company is “working closely with hardware manufactures to help mitigate the issue.”
Author Alan Martin, ESET