Observable discrepancy in Linux kernel - CVE-2023-3640

 

Observable discrepancy in Linux kernel - CVE-2023-3640

Published: July 24, 2023 / Updated: June 21, 2024


Vulnerability identifier: #VU92728
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/U:Clear
CVE-ID: CVE-2023-3640
CWE-ID: CWE-203
Exploitation vector: Local access
Exploit availability: Public exploit is available
Vendor: Linux Foundation
Affected software:
Linux kernel

Detailed vulnerability description

The vulnerability allows a local user to execute arbitrary code.

A possible unauthorized memory access flaw was found in the Linux kernel's cpu_entry_area mapping of X86 CPU data to memory, where a user may guess the location of exception stacks or other important data. Based on the previous CVE-2023-0597, the 'Randomize per-cpu entry area' feature was implemented in /arch/x86/mm/cpu_entry_area.c, which works through the init_cea_offsets() function when KASLR is enabled. However, despite this feature, there is still a risk of per-cpu entry area leaks. This issue could allow a local user to gain access to some important data with memory in an expected location and potentially escalate their privileges on the system.


How to mitigate CVE-2023-3640

Install update from vendor's repository.

Sources