PT-2021-4034 · Linux+4 · Linux Kernel+4

Michael Wakabayashi · Published 2021-06-13 · Updated 2023-05-17 · CVE-2021-38199

Positive Technologies (AI Summary)

CVSS v3.1

6.5

Medium

Base vector

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

Name of the Vulnerable Software and Affected Versions Linux kernel versions prior to 5.13.4

Description The issue is related to incorrect connection-setup ordering in the Linux kernel, specifically in the fs/nfs/nfs4client.c file. This allows operators of remote NFSv4 servers to cause a denial of service by making those servers unreachable during trunking detection, resulting in hanging mounts.

Recommendations For versions prior to 5.13.4, update to version 5.13.4 or later to resolve the issue. As a temporary workaround, consider restricting access to remote NFSv4 servers to minimize the risk of exploitation.

Fix

Improper Initialization

Weakness Enumeration

CWE-665

Related Identifiers

ALT-PU-2021-2284

ALT-PU-2021-2486

ALT-PU-2021-2616

ALT-PU-2021-3563

ALT-PU-2021-3573

ALT-PU-2022-1240

ALT-PU-2022-1419

ALT-PU-2022-1421

ALT-PU-2023-1814

AZL-6583

BDU:2021-04561

CVE-2021-38199

DLA-2785-1

DLA-2843-1

DSA-4978-1

OESA-2021-1318

USN-5091-1

USN-5091-2

USN-5091-3

USN-5092-1

USN-5092-2

USN-5092-3

USN-5096-1

USN-5106-1

USN-5120-1

USN-5136-1

Affected Products

Alt Linux

Astra Linux

Linuxmint

Linux Kernel

Ubuntu

References · 96

• https://github.com/torvalds/linux/commit/dd99e9f98fbf423ff6d365b37a98e8879170f17c · Patch
• https://ubuntu.com/security/CVE-2021-42252 · Vendor Advisory
• https://ubuntu.com/security/notices/USN-5096-1 · Vendor Advisory
• https://ubuntu.com/security/CVE-2021-3655 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2021-3679 · Security Note
• https://ubuntu.com/security/CVE-2020-26541 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2021-38205 · Security Note
• https://ubuntu.com/security/CVE-2021-38160 · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2021-38199 · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2021-38199 · Vendor Advisory
• https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.13.4 · Vendor Advisory
• https://osv.dev/vulnerability/OESA-2021-1318 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2021-38199 · Security Note
• https://ubuntu.com/security/CVE-2021-35477 · Vendor Advisory
• https://ubuntu.com/security/notices/USN-5091-2 · Vendor Advisory