CVE-2021-0606

Local privilege escalation via sync-object refcount imbalance

Published Jun 22, 2021 · Updated Aug 3, 2024

Use-after-free in Android kernel GPU DRM Driver allows local users with System privileges to gain additional privileges via a sync-object ioctl. The drm_syncobj_handle_to_fd function increments a found sync object's reference count again after successful file-descriptor export, leaving the reference count imbalanced. Exploitation requires local System execution privileges and no user interaction, and successful abuse yields higher privileges on the device.

CVSS severity6.7
Medium
EPSS probability0.15%
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 Android kernel GPU DRM Driver allows local users with System privileges to gain additional privileges via a sync-object ioctl. The drm_syncobj_handle_to_fd function increments a found sync object's reference count again after successful file-descriptor export, leaving the reference count imbalanced. Exploitation requires local System execution privileges and no user interaction, and successful abuse yields higher privileges on the device.

The record

CVE
CVE-2021-0606
Published
Jun 22, 2021
Updated
Aug 3, 2024
Vendor
Google Cloud
Product
Android
Classifications
CWE-416, T1404
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Jun 22, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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=Android kernel

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

Google Cloud · Androidversion=Android kernel

Published CVSS scores

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

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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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 exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free
T1404Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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