CVE-2021-25471Network attack vector

Mobile service interruption via replayed security commands

Published Oct 6, 2021 · Updated Aug 3, 2024

Improper input validation in Samsung Mobile Devices before SMR Oct-2021 Release 1 allows remote attackers to interrupt mobile service. The Security Mode Command process accepts replayed commands because it does not verify the NAS count used to detect stale messages. Exploitation targets O(8.1), P(9.0), or Q(10.0) devices with Exynos CP chipsets and disrupts the mobile-network connection while depleting the battery.

CVSS severity3.7
Low
EPSS probability0.40%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Improper input validation in Samsung Mobile Devices before SMR Oct-2021 Release 1 allows remote attackers to interrupt mobile service. The Security Mode Command process accepts replayed commands because it does not verify the NAS count used to detect stale messages. Exploitation targets O(8.1), P(9.0), or Q(10.0) devices with Exynos CP chipsets and disrupts the mobile-network connection while depleting the battery.

The record

CVE
CVE-2021-25471
Published
Oct 6, 2021
Updated
Aug 3, 2024
Vendor
Samsung Electronics Co., Ltd.
Product
Samsung Mobile Devices
Classifications
CWE-20, T1642
Attack vector
network
Privileges
unauthenticated

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

Compare your product and version with the public record. A matching version still requires validation against your environment.

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) devices with Exynos CP chipsets <SMR Oct-2021 Release 1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Samsung Electronics Co., Ltd. · Samsung Mobile Devicesversion=O(8.1), P(9.0), Q(10.0) devices with Exynos CP chipsets <SMR Oct-2021 Release 1

Published CVSS scores

5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:N/A:P
3.7Samsung MobileCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-20Improper Input Validation
T1642Endpoint Denial of Service

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo