Advisory Details

July 6th, 2023

(Pwn2Own) Linux Kernel nftables Incorrect Pointer Scaling Local Privilege Escalation Vulnerability

ZDI-23-900
ZDI-CAN-20721

CVE ID CVE-2023-35001
CVSS SCORE 7.8, AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
AFFECTED VENDORS Linux
AFFECTED PRODUCTS Kernel
VULNERABILITY DETAILS

This vulnerability allows local attackers to escalate privileges on affected installations of Linux Kernel. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability.

The specific flaw exists within the processing of nft chains. The issue results from incorrect pointer scaling, which can result in a memory access past the end of an array. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of the kernel.

ADDITIONAL DETAILS Linux has issued an update to correct this vulnerability. More details can be found at:
https://lore.kernel.org/netfilter-devel/20230705121515.747251-1-cascardo@canonical.com/T/
DISCLOSURE TIMELINE
  • 2023-05-09 - Vulnerability reported to vendor
  • 2023-07-06 - Coordinated public release of advisory
CREDIT Tanguy DUBROCA (@SidewayRE) from Synacktiv (@Synacktiv)
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