CVE-2021-42327Public exploit

Local privilege escalation via debugfs heap overflow

Published Oct 21, 2021 · Updated Aug 4, 2024

Heap-based buffer overflow in the Linux kernel through 5.14.14 allows local users to escalate privileges through AMDGPU debugfs. parse_write_buffer_into_params passes the user-controlled write length to copy_from_user, which copies into a fixed 40-byte heap buffer without a bound check. Exploitation requires the AMDGPU display driver, debugfs, and write access to the affected entry; successful corruption can crash the system or execute code with kernel privileges.

CVSS severity6.7
Medium
EPSS probability0.87%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap-based buffer overflow in the Linux kernel through 5.14.14 allows local users to escalate privileges through AMDGPU debugfs. parse_write_buffer_into_params passes the user-controlled write length to copy_from_user, which copies into a fixed 40-byte heap buffer without a bound check. Exploitation requires the AMDGPU display driver, debugfs, and write access to the affected entry; successful corruption can crash the system or execute code with kernel privileges.

The record

CVE
CVE-2021-42327
Published
Oct 21, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787, T1068
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Oct 21, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

4.6NIST NVDAV:L/AC:L/Au:N/C:P/I:P/A:P
6.7NIST NVDCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-787Out-of-bounds Write
T1068Exploitation for Privilege Escalation

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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