CVE-2021-25407

Arbitrary memory write via unchecked NPU bounds

Published Jun 11, 2021 · Updated Aug 3, 2024

Out-of-bounds write in the NPU driver in Samsung Mobile Devices before SMR JUN-2021 Release 1 allows local users to write arbitrary memory. The npu_session_format path performs a memory write without verifying that the destination remains within its buffer. Low-privilege local access on an affected Android 9.0, 10.0, or 11.0 device with an Exynos 9820, 9830, 980, or 2100 chipset is required, and memory integrity is the directly documented consequence.

CVSS severity7.8
High
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds write in the NPU driver in Samsung Mobile Devices before SMR JUN-2021 Release 1 allows local users to write arbitrary memory. The npu_session_format path performs a memory write without verifying that the destination remains within its buffer. Low-privilege local access on an affected Android 9.0, 10.0, or 11.0 device with an Exynos 9820, 9830, 980, or 2100 chipset is required, and memory integrity is the directly documented consequence.

The record

CVE
CVE-2021-25407
Published
Jun 11, 2021
Updated
Aug 3, 2024
Vendor
Samsung Electronics Co., Ltd.
Product
Samsung Mobile Devices
Classifications
CWE-787, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 11, 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) devices with Exynos9820, 9830, 980, 2100 chipsets <SMR JUN-2021 Release 1

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Samsung Electronics Co., Ltd. · Samsung Mobile Devicesversion=P(9.0), Q(10.0), R(11.0) devices with Exynos9820, 9830, 980, 2100 chipsets <SMR JUN-2021 Release 1

Published CVSS scores

4.6NVDAV:L/AC:L/Au:N/C:P/I:P/A:P
7.8NVDCVSS:3.1/AV:L/AC:L/PR:L/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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 exploitUnconfirmed

Weakness, pattern, technique

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

Public exploit references

No public exploit references are available in this record.

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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