CVE-2023-20696Public exploit

Local privilege escalation via missing preloader bounds check

Published May 15, 2023 · Updated Jan 23, 2025

An out-of-bounds write in the MediaTek preloader on Android 13 and OpenWrt 19.07 or 21.02 allows local users to gain elevated privileges. The preloader processes input without a required bounds check, allowing a write beyond the intended memory boundary. Exploitation requires existing System execution privileges and no user interaction, and the resulting memory corruption enables local privilege escalation.

CVSS severity6.7
Medium
EPSS probability0.10%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

An out-of-bounds write in the MediaTek preloader on Android 13 and OpenWrt 19.07 or 21.02 allows local users to gain elevated privileges. The preloader processes input without a required bounds check, allowing a write beyond the intended memory boundary. Exploitation requires existing System execution privileges and no user interaction, and the resulting memory corruption enables local privilege escalation.

The record

CVE
CVE-2023-20696
Published
May 15, 2023
Updated
Jan 23, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787, CWE-20, T1404, T1068
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. May 15, 2023CVE publishedPublication date reported by the CVE source.
  2. Jan 23, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.7NVDCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
6.7CISA-ADPCVSS: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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-787Out-of-bounds Write
CWE-20Improper Input Validation
T1404Exploitation for Privilege Escalation
T1068Exploitation for Privilege Escalation

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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