CVE-2025-21020

Memory corruption via unvalidated bitmap creation

Published Aug 6, 2025 · Updated Feb 26, 2026

Out-of-bounds write in Samsung Blockchain Keystore before 1.3.17.2 allows local users with high privileges to write beyond allocated memory. The bitmap-image creation path fails to validate input bounds before writing to memory. The flaw is reachable only with high local privileges, and Samsung has not disclosed whether the write enables code execution.

CVSS severity5.7
Medium
EPSS probability0.13%
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

Out-of-bounds write in Samsung Blockchain Keystore before 1.3.17.2 allows local users with high privileges to write beyond allocated memory. The bitmap-image creation path fails to validate input bounds before writing to memory. The flaw is reachable only with high local privileges, and Samsung has not disclosed whether the write enables code execution.

The record

CVE
CVE-2025-21020
Published
Aug 6, 2025
Updated
Feb 26, 2026
Vendor
Samsung Electronics
Product
Samsung Blockchain Keystore
Classifications
CWE-787
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Aug 6, 2025CVE publishedPublication date reported by the CVE source.
  2. Feb 26, 2026Record 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?

Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

Samsung Electronics · Samsung Blockchain KeystoreAffected versions are unavailable in this record.

Published CVSS scores

6.7NIST NVDCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
5.7Samsung MobileCVSS:3.1/AV:L/AC:H/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.

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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write

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