CVE-2020-27820Public exploit

System crash via nouveau postclose use-after-free

Published Nov 2, 2021 · Updated Aug 4, 2024

Use-after-free in the Linux kernel nouveau driver allows attackers to crash the system by unbinding or removing a graphics device. Device removal frees the entire nouveau_drm structure while userspace can retain an open device file, so postclose() later dereferences freed memory. Exploitation requires privileged local access to unbind the driver or physical proximity to remove a bound graphics device.

CVSS severity4.7
Medium
EPSS probability0.50%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in the Linux kernel nouveau driver allows attackers to crash the system by unbinding or removing a graphics device. Device removal frees the entire nouveau_drm structure while userspace can retain an open device file, so postclose() later dereferences freed memory. Exploitation requires privileged local access to unbind the driver or physical proximity to remove a bound graphics device.

The record

CVE
CVE-2020-27820
Published
Nov 2, 2021
Updated
Aug 4, 2024
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-416, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Nov 2, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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  1. Affected versionversion=to be fixed in RHEL-9 release

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=to be fixed in RHEL-9 release

Published CVSS scores

4.7NIST NVDAV:L/AC:M/Au:N/C:N/I:N/A:C
4.7NIST NVDCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-416Use After Free
T1499Endpoint Denial of Service

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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