8.8

CVE-2021-3493

Warnung
Medienbericht
Exploit
The overlayfs implementation in the linux kernel did not properly validate with respect to user namespaces the setting of file capabilities on files in an underlying file system. Due to the combination of unprivileged user namespaces along with a patch carried in the Ubuntu kernel to allow unprivileged overlay mounts, an attacker could use this to gain elevated privileges.
Daten sind bereitgestellt durch National Vulnerability Database (NVD)
Canonical ≫ Ubuntu Linux SwEditionlts Version < 18.04
Canonical ≫ Ubuntu Linux SwEditionlts Version >= 18.04.1 < 20.04
Canonical ≫ Ubuntu Linux SwEdition- Version < 20.10
VulnDex Vulnerability Enrichment
Diese Information steht angemeldeten Benutzern zur Verfügung. Login Login

20.10.2022: CISA Known Exploited Vulnerabilities (KEV) Catalog

Linux Kernel Privilege Escalation Vulnerability

Schwachstelle

The overlayfs stacking file system in Linux kernel does not properly validate the application of file capabilities against user namespaces, which could lead to privilege escalation.

Beschreibung

Apply updates per vendor instructions.

Erforderliche Maßnahmen
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 43.99% 0.986
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
nvd@nist.gov 7.8 1.8 5.9
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
nvd@nist.gov 7.2 3.9 10
AV:L/AC:L/Au:N/C:C/I:C/A:C
security@ubuntu.com 8.8 2 6
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
CWE-270 Privilege Context Switching Error

The product does not properly manage privileges while it is switching between different contexts that have different privileges or spheres of control.

CWE-863 Incorrect Authorization

The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.

http://packetstormsecurity.com/files/162434/Kernel-Live-Patch-Security-Notice-LSN-0076-1.html
Third Party Advisory
Exploit
VDB Entry
https://ubuntu.com/security/notices/USN-4917-1
Vendor Advisory
http://packetstormsecurity.com/files/162866/Ubuntu-OverlayFS-Local-Privilege-Escalation.html
Third Party Advisory
VDB Entry
Press/Media Coverage
http://packetstormsecurity.com/files/165151/Ubuntu-Overlayfs-Local-Privilege-Escalation.html
Third Party Advisory
Exploit
VDB Entry
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7c03e2cda4a584cadc398e8f6641ca9988a39d52
Patch
Third Party Advisory
Mailing List
https://www.openwall.com/lists/oss-security/2021/04/16/1
Third Party Advisory
Mailing List
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-3493
US Government Resource