PT-2021-2217 · Linux+6 · Linux Kernel+6

Alexander Popov · Published 2021-02-01 · Updated 2024-12-19 · CVE-2021-26708

Positive Technologies (AI Summary)

CVSS v3.1

7.0

High

Base vector

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

Name of the Vulnerable Software and Affected Versions Linux kernel versions prior to 5.10.13

Description A local privilege escalation issue is present in the Linux kernel due to multiple race conditions in the AF VSOCK implementation. These conditions are caused by incorrect locking in the net/vmw vsock/af vsock.c file. The issue was introduced when VSOCK multi-transport support was added.

Recommendations For Linux kernel versions prior to 5.10.13, update to version 5.10.13 or later to resolve the issue. As a temporary workaround, consider restricting access to the AF VSOCK implementation until a patch is available.

Exploit

Fix

LPE

Improper Privilege Management

Improper Locking

Race Condition

Weakness Enumeration

CWE-269

CWE-667

CWE-362

Related Identifiers

ALSA-2021:1093

ALT-PU-2021-1208

ALT-PU-2021-1249

ALT-PU-2021-1339

ALT-PU-2021-1417

ALT-PU-2021-1424

ALT-PU-2021-1446

BDU:2021-01126

CESA-2021_1081

CESA-2021_1093

CVE-2021-26708

MGASA-2021-0084

MGASA-2021-0085

OPENSUSE-SU-2024:10728-1

OPENSUSE-SU-2024:13704-1

RHSA-2021:1081

RHSA-2021:1093

RHSA-2021_1081

RHSA-2021_1093

USN-4727-1

Affected Products

Alt Linux

Almalinux

Centos

Linuxmint

Linux Kernel

Red Hat

Ubuntu

References · 266

• 🔥 https://github.com/jordan9001/vsock_poc · Exploit
• https://linux.oracle.com/errata/ELSA-2021-1093.html · Vendor Advisory
• https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.10.13 · Vendor Advisory
• https://openwall.com/lists/oss-security/2021/02/04/5 · Patch
• https://bdu.fstec.ru/vul/2021-01126 · Security Note
• https://advisories.mageia.org/MGASA-2021-0085.html · Security Note
• https://security.netapp.com/advisory/ntap-20210312-0008 · Patch
• https://ubuntu.com/security/notices/USN-4727-1 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2021-26708 · Security Note
• https://osv.dev/vulnerability/CVE-2021-26708 · Vendor Advisory
• https://ubuntu.com/security/CVE-2021-26708 · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2021-26708 · Vendor Advisory
• https://osv.dev/vulnerability/MGASA-2021-0085 · Vendor Advisory
• http://openwall.com/lists/oss-security/2021/02/05/6 · Patch
• https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c518adafa39f37858697ac9309c6cf1805581446 · Vendor Advisory