CVE-2021-47281

Public on

Last Modified: UTC

Description

A vulnerability was found in the Linux kernel's ALSA sequencer, where the snd_seq_timer_open() function fails to properly manage concurrent access to timer instances, which could allow multiple calls to override the timer, leading to a potential use-after-free issue if a timer continues running after its associated queue is closed.

A vulnerability was found in the Linux kernel's ALSA sequencer, where the snd_seq_timer_open() function fails to properly manage concurrent access to timer instances, which could allow multiple calls to override the timer, leading to a potential use-after-free issue if a timer continues running after its associated queue is closed.

Mitigation

Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.

Additional information

  • Bugzilla 2282516: kernel: ALSA: seq: Fix race of snd_seq_timer_open()
  • CWE-416: Use After Free
  • FAQ: Frequently asked questions about CVE-2021-47281

Common Vulnerability Scoring System (CVSS) Score Details

Important note

CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).

The following CVSS metrics and score provided are preliminary and subject to review.

CVSS v3 Score Breakdown
Red HatNVD

CVSS v3 Base Score

5.8

7

Attack Vector

Local

Local

Attack Complexity

High

High

Privileges Required

Low

Low

User Interaction

None

None

Scope

Unchanged

Unchanged

Confidentiality Impact

Low

High

Integrity Impact

Low

High

Availability Impact

High

High

CVSS v3 Vector

Red Hat: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:H

NVD: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Frequently Asked Questions

Why is Red Hat's CVSS v3 score or Impact different from other vendors?

My product is listed as "Under investigation" or "Affected", when will Red Hat release a fix for this vulnerability?

What can I do if my product is listed as "Will not fix"?

What can I do if my product is listed as "Fix deferred"?

What is a mitigation?

I have a Red Hat product but it is not in the above list, is it affected?

Why is my security scanner reporting my product as vulnerable to this vulnerability even though my product version is fixed or not affected?

My product is listed as "Out of Support Scope". What does this mean?

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