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: 8.5 [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]
CVE-ID: CVE-2023-3640
CWE-ID: CWE-203
Exploitation vector: Local access
Exploit availability: Public exploit is available

Vulnerability details

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.


Affected software

Linux kernel
IBM Storage Scale System

How to mitigate CVE-2023-3640

Install update from vendor's repository.

IBM Storage Scale System - addressed in versions 6.1.9.5, 6.2.2.0

Links to Public Exploits and PoC-codes

External References

Related Security Bulletins