CVE-2023-2640

Published on: Not Yet Published

Last Modified on: 08/03/2023 03:10:00 PM UTC

CVE-2023-2640

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Certain versions of Ubuntu Linux from Canonical contain the following vulnerability:

On Ubuntu kernels carrying both c914c0e27eb0 and "UBUNTU: SAUCE: overlayfs: Skip permission checking for trusted.overlayfs.* xattrs", an unprivileged user may set privileged extended attributes on the mounted files, leading them to be set on the upper files without the appropriate security checks.

CVE-2023-2640 has been assigned by secu[email protected] to track the vulnerability - currently rated as HIGH severity.
Affected Vendor/Software: Canonical - Ubuntu Kernel version not down converted

Vulnerability Patch/Work Around

If not needed, disable the ability for unprivileged users to create namespaces. To do this temporarily, do: sudo sysctl -w kernel.unprivileged_userns_clone=0 To disable across reboots, do: echo kernel.unprivileged_userns_clone=0 | \ sudo tee /etc/sysctl.d/99-disable-unpriv-userns.conf

CVSS3 Score: 7.8 - HIGH

Attack Vector ^ⓘ	Attack Complexity	Privileges Required	User Interaction
LOCAL	LOW	LOW	NONE
Scope	Confidentiality Impact	Integrity Impact	Availability Impact
UNCHANGED	HIGH	HIGH	HIGH

CVE References

Description	Tags ^ⓘ	Link
[SRU Kinetic, Lunar, OEM-6.1 2/3] Revert "UBUNTU: SAUCE: overlayfs: Skip permission checking for trusted.overlayfs.* xattrs"	lists.ubuntu.com text/x-diff	MISC lists.ubuntu.com/archives/kernel-team/2023-July/140923.html
Page not found \| Wiz	wiz.io text/html Inactive LinkNot Archived	MISC wiz.io/blog/ubuntu-overlayfs-vulnerability
CVE - CVE-2023-2640	cve.mitre.org text/xml	MISC cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-2640
USN-6250-1: Linux kernel vulnerabilities \| Ubuntu security notices \| Ubuntu	ubuntu.com text/html	MISC ubuntu.com/security/notices/USN-6250-1

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Related QID Numbers

199608 Ubuntu Security Notification for Linux kernel Vulnerabilities (USN-6250-1)
199610 Ubuntu Security Notification for Linux kernel (OEM) Vulnerabilities (USN-6248-1)
199618 Ubuntu Security Notification for Linux kernel Vulnerabilities (USN-6260-1)
199651 Ubuntu Security Notification for Linux kernel (OEM) Vulnerabilities (USN-6285-1)

Known Affected Configurations (CPE V2.3)

Type	Vendor	Product	Version	Update	Edition	Language
Operating System	Canonical	Ubuntu Linux	23.04	All	All	All

cpe:2.3:o:canonical:ubuntu_linux:23.04:*:*:*:*:*:*:*:

No vendor comments have been submitted for this CVE

Social Mentions

Source	Title	Posted (UTC)
/r/pop_os	Is PopOS vulnerable to CVE-2023-2640 and CVE-2023-32629	2023-07-27 06:32:03
/r/sysadmin	GameOver(lay): Easy-to-exploit local privilege escalation vulnerabilities in Ubuntu Linux affect 40% of Ubuntu cloud workloads	2023-07-27 15:42:28
/r/KibernetinisSaugumas	Ubuntu branduolio pažeidžiamumai kelia grėsmę milijonams naudotojų	2023-07-28 10:37:11
/r/selfhosted	Ubuntu Local Privilege Escalation (CVE-2023-2640 & CVE-2023-32629)	2023-07-31 10:46:42
/r/Action1	Patch Tuesday August 2023	2023-08-08 17:42:04
/r/hacking	"Analysis" of a Raspberry Pi 400 a redditor got a week ago	2023-09-03 19:29:15