PT-2020-6011 · Linux · Linux Kernel

Guilherme De Almeida Suckevicz + 1 · Published 2020-09-30 · Updated 2023-07-28 · CVE-2021-20226

Positive Technologies (AI Summary)

CVSS v3.1

7.8

High

Base vector

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

Name of the Vulnerable Software and Affected Versions Linux Kernel (affected versions not specified)

Description A use-after-free flaw was found in the io uring in Linux kernel, where a local attacker with user privilege could cause a denial of service problem on the system. The issue results from the lack of validating the existence of an object prior to performing operations on the object by not incrementing the file reference counter while in use. The highest threat from this vulnerability is to data integrity, confidentiality, and system availability.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Use After Free

Weakness Enumeration

CWE-416

Related Identifiers

BDU:2021-02596

CVE-2021-20226

ZDI-21-001

Affected Products

Linux Kernel

References · 31

• https://osv.dev/vulnerability/DEBIAN-CVE-2021-20226 · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2021-20226 · Vendor Advisory
• https://zerodayinitiative.com/advisories/ZDI-21-001 · Security Note
• https://security-tracker.debian.org/tracker/CVE-2021-20226 · Vendor Advisory
• https://bdu.fstec.ru/vul/2021-02596 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2021-20226 · Security Note
• https://ubuntu.com/security/CVE-2021-20226 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2021-20226 · Security Note
• https://osv.dev/vulnerability/CVE-2021-20226 · Vendor Advisory
• https://t.me/ckure/12094 · Telegram Post
• https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=cdc8fcb49905c0b67e355e027cb462ee168ffaa3 · Note
• https://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.9.3 · Note
• https://security.netapp.com/advisory/ntap-20210401-0001 · Note
• https://openwall.com/lists/oss-security/2021/02/05/4 · Note
• https://zerodayinitiative.com/blog/2021/4/22/cve-2021-20226-a-reference-counting-bug-in-the-linux-kernel-iouring-subsystem · Note