CVE-2021-25490Public exploit

Private-key recovery via legacy keyblob downgrade

Published Oct 6, 2021 · Updated Aug 3, 2024

Keyblob downgrade in Samsung Mobile Devices before SMR Oct-2021 Release 1 allows local users to recover hardware-protected private keys. Keymaster trusts the client-controlled KM_EKEY_BLOB_ENC_VER tag, selects legacy v15 encryption with a deterministic KDF, and reuses an AES-GCM IV. Root or equivalent code execution in the privileged Keystore context is required; recovered keys can bypass FIDO2 presence checks and expose imported secrets.

CVSS severity6.0
Medium
EPSS probability0.75%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Keyblob downgrade in Samsung Mobile Devices before SMR Oct-2021 Release 1 allows local users to recover hardware-protected private keys. Keymaster trusts the client-controlled KM_EKEY_BLOB_ENC_VER tag, selects legacy v15 encryption with a deterministic KDF, and reuses an AES-GCM IV. Root or equivalent code execution in the privileged Keystore context is required; recovered keys can bypass FIDO2 presence checks and expose imported secrets.

The record

CVE
CVE-2021-25490
Published
Oct 6, 2021
Updated
Aug 3, 2024
Vendor
Samsung Electronics Co., Ltd.
Product
Samsung Mobile Devices
Classifications
CWE-287, T1552.004
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

3.6NIST NVDAV:L/AC:L/Au:N/C:P/I:P/A:N
6.0Samsung MobileCVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:L
6.0NIST NVDCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N

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 exploitPublished

Weakness, pattern, technique

CWE-287Improper Authentication
T1552.004Unsecured Credentials: Private Keys

Public exploit references

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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