SB2023072449 - Observable discrepancy in Linux kernel

Description

This security bulletin contains information about 1 vulnerability.

1) Observable discrepancy (CVE-ID: CVE-2023-3640)

CWE-ID: CWE-203 - Observable discrepancy

CVSSv4: 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

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.

Remediation

Install update from vendor's website.

References

• https://bugzilla.redhat.com/show_bug.cgi?id=2217523
• https://access.redhat.com/security/cve/CVE-2023-3640