CVE-2023-21509

Local code execution via screen-update buffer overwrite

Published May 4, 2023 · Updated Feb 12, 2025

Out-of-bounds write in Samsung Blockchain Keystore before 1.3.12.1 allows local users to execute arbitrary code through a TUI command. The bc_tui trustlet mishandles BC_TUI_CMD_UPDATE_SCREEN input and writes beyond the intended buffer while updating the screen. Exploitation requires privileged local access to a supported Galaxy device and enables code execution within the trustlet context.

CVSS severity6.7
Medium
EPSS probability0.19%
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 Samsung Blockchain Keystore before 1.3.12.1 allows local users to execute arbitrary code through a TUI command. The bc_tui trustlet mishandles BC_TUI_CMD_UPDATE_SCREEN input and writes beyond the intended buffer while updating the screen. Exploitation requires privileged local access to a supported Galaxy device and enables code execution within the trustlet context.

The record

CVE
CVE-2023-21509
Published
May 4, 2023
Updated
Feb 12, 2025
Vendor
Samsung Electronics
Product
Samsung Blockchain Keystore
Classifications
CWE-787, T1658
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. May 4, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 12, 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=unspecified <1.3.12.1

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

Samsung Electronics · Samsung Blockchain Keystoreversion=unspecified <1.3.12.1

Published CVSS scores

7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
6.7Samsung MobileCVSS:3.1/AV:L/AC:L/PR:H/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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write
T1658Exploitation for Client Execution

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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