CVE-2023-2640

Canonical Ubuntu OverlayFS File System Missing Authorization Local Privilege Escalation Vulnerability

Severity Score

7.8

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

Track*

*SSVC

Descriptions

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.

This vulnerability allows local attackers to escalate privileges on affected installations of Canonical Ubuntu. 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 handling of attributes. The issue results from missing authorization before allowing access to functionality. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of root.

*Credits: Stonejiajia, Shir Tamari, Sagi Tzadik

CVSS Scores

NISTv3.1 7.8

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

* Common Vulnerability Scoring System

SSVC

Decision:Track*

Exploitation

None

Automatable

Tech. Impact

Total

* Organization's Worst-case Scenario

Timeline

2023-05-10 CVE Reserved
2023-07-26 CVE Published
2023-10-09 First Exploit
2024-10-04 EPSS Updated
2024-10-23 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date

CWE

CWE-863: Incorrect Authorization

CAPEC

References (10)

URL	Tag	Source
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-2640	Issue Tracking

URL	Date	SRC
https://github.com/ThrynSec/CVE-2023-32629-CVE-2023-2640---POC-Escalation	2023-11-15
https://github.com/xS9NTX/CVE-2023-32629-CVE-2023-2640-Ubuntu-Privilege-Escalation-POC	2023-11-14
https://github.com/g1vi/CVE-2023-2640-CVE-2023-32629	2023-10-09
https://github.com/Nkipohcs/CVE-2023-2640-CVE-2023-32629	2024-03-19
https://github.com/musorblyat/CVE-2023-2640-CVE-2023-32629	2023-11-02
https://github.com/K5LK/CVE-2023-2640-32629	2024-05-22
https://wiz.io/blog/ubuntu-overlayfs-vulnerability	2024-10-23

URL	Date	SRC
https://lists.ubuntu.com/archives/kernel-team/2023-July/140923.html	2023-08-03

URL	Date	SRC
https://ubuntu.com/security/notices/USN-6250-1	2023-08-03

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Canonical Search vendor "Canonical"		Ubuntu Linux Search vendor "Canonical" for product "Ubuntu Linux"				23.04 Search vendor "Canonical" for product "Ubuntu Linux" and version "23.04"		-		Affected