CVE-2021-25491

Device reboot via unchecked DMA mapping return

Published Oct 6, 2021 · Updated Aug 3, 2024

NULL-pointer dereference in the MFC driver on selected Samsung Mobile Devices before SMR Oct-2021 Release 1 allows local users to reboot them. The mfc_mem_ion_alloc path checks dma_buf_vmap's NULL error return with IS_ERR and then treats the result as a valid kernel mapping. SELinux restricts the affected video-device node to privileged processes; a large user-supplied ION buffer can force a reboot, and repeated triggers can create a crash loop.

CVSS severity2.3
Low
EPSS probability0.10%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL-pointer dereference in the MFC driver on selected Samsung Mobile Devices before SMR Oct-2021 Release 1 allows local users to reboot them. The mfc_mem_ion_alloc path checks dma_buf_vmap's NULL error return with IS_ERR and then treats the result as a valid kernel mapping. SELinux restricts the affected video-device node to privileged processes; a large user-supplied ION buffer can force a reboot, and repeated triggers can create a crash loop.

The record

CVE
CVE-2021-25491
Published
Oct 6, 2021
Updated
Aug 3, 2024
Vendor
Samsung Electronics Co., Ltd.
Product
Samsung Mobile Devices
Classifications
CWE-476, T1642
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Oct 6, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=P(9.0), Q(10.0), R(11.0) <SMR Oct-2021 Release 1

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

Samsung Electronics Co., Ltd. · Samsung Mobile Devicesversion=P(9.0), Q(10.0), R(11.0) <SMR Oct-2021 Release 1

Published CVSS scores

4.4NIST NVDCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
2.1NIST NVDAV:L/AC:L/Au:N/C:N/I:N/A:P
2.3Samsung MobileCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L

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 exploitUnconfirmed

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
T1642Endpoint Denial of Service

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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