Quote:An information-disclosure security vulnerability has been discovered in the Linux kernel, which can be exploited to expose information in the kernel stack memory of vulnerable devices.
 
Specifically, the bug (CVE-2020-28588) exists in the /proc/pid/syscall functionality of 32-bit ARM devices running Linux, according to Cisco Talos, which discovered the vulnerability. It arises from an improper conversion of numeric values when reading the file.
 
With a few commands, attackers can output 24 bytes of uninitialized stack memory, which can be used to bypass kernel address space layout randomization (KASLR). KASLR is an anti-exploit technique that places various objects at random to prevent predictable patterns that are guessable by adversaries.
 
Attacks also would be “impossible to detect on a network remotely,” the firm explained. And, “if utilized correctly, an attacker could leverage this information leak to successfully exploit additional unpatched Linux vulnerabilities.”

Quote:Cisco Talos researchers first discovered the issue on an Azure Sphere device (version 20.10), a 32-bit ARM device that runs a patched Linux kernel. It’s been present since v5.1-rc4 of the kernel.
 
“Users are encouraged to update these affected products as soon as possible: Linux Kernel versions 5.10-rc4, 5.4.66 and 5.9.8,” according to the advisory. “Talos tested and confirmed these versions of the Linux kernel could be exploited by this vulnerability.”