CVE-2024-20820Public exploit

ATF memory disclosure via unchecked SMC index

Published Feb 6, 2024 · Updated Aug 1, 2024

Out-of-bounds read in the bootloader of Samsung Mobile Devices before SMR Feb-2024 Release 1 allows local privileged users to read ATF memory. The mediatek_plat_sip_handler_kernel path accepts an attacker-controlled SMC index without bounds checking and returns four bytes from the indexed ATF virtual address. Root-level access to a selected Android 11, 12, or 13 MediaTek device is required, and disclosure is confined to ARM Trusted Firmware data.

CVSS severity4.4
Medium
EPSS probability0.20%
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 read in the bootloader of Samsung Mobile Devices before SMR Feb-2024 Release 1 allows local privileged users to read ATF memory. The mediatek_plat_sip_handler_kernel path accepts an attacker-controlled SMC index without bounds checking and returns four bytes from the indexed ATF virtual address. Root-level access to a selected Android 11, 12, or 13 MediaTek device is required, and disclosure is confined to ARM Trusted Firmware data.

The record

CVE
CVE-2024-20820
Published
Feb 6, 2024
Updated
Aug 1, 2024
Vendor
Samsung Electronics Co., Ltd.
Product
Samsung Mobile Devices
Classifications
CWE-125, T1005
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Feb 6, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 1, 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?

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 Co., Ltd. · Samsung Mobile DevicesAffected versions are unavailable in this record.

Published CVSS scores

4.4Samsung MobileCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N
7.1NISTCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/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)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-125Out-of-bounds Read
T1005Data from Local System

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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