CVE-2021-25487Known exploitation

Local code execution via unchecked modem buffer

Published Oct 6, 2021 · Updated Oct 21, 2025

Out-of-bounds read in Samsung Mobile Devices before SMR Oct-2021 Release 1 allows local users to execute arbitrary code. set_skb_priv() in the modem interface driver reads past a buffer because it does not validate the boundary, then dereferences an invalid function pointer. Exploitation requires low-privileged local access on an affected Exynos device and can execute code across a security boundary.

CVSS severity7.3
High
EPSS probability0.64%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in Samsung Mobile Devices before SMR Oct-2021 Release 1 allows local users to execute arbitrary code. set_skb_priv() in the modem interface driver reads past a buffer because it does not validate the boundary, then dereferences an invalid function pointer. Exploitation requires low-privileged local access on an affected Exynos device and can execute code across a security boundary.

The record

CVE
CVE-2021-25487
Published
Oct 6, 2021
Updated
Oct 21, 2025
Vendor
Samsung Electronics Co., Ltd.
Product
Samsung Mobile Devices
Classifications
CWE-125, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 6, 2021CVE publishedPublication date reported by the CVE source.
  2. Jun 29, 2023Exploitation reportedCISA Known Exploited Vulnerabilities Catalog listing
  3. Oct 21, 2025Record 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=O(8.1), P(9.0), Q(10.0), R(11.0) <SMR Oct-2021 Release 1

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Samsung Electronics Co., Ltd. · Samsung Mobile Devicesversion=O(8.1), P(9.0), Q(10.0), R(11.0) <SMR Oct-2021 Release 1

Published CVSS scores

4.6NVDAV:L/AC:L/Au:N/C:P/I:P/A:P
7.3Samsung MobileCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N
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 exploitationReported
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-125Out-of-bounds Read
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.

Reported exploitation

Technologies

Your stack

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Your stack

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