CVE-2023-21256 – This vulnerability in Android's Settings app al... (How to Fix)

Q: What is the severity of CVE-2023-21256?

CVE-2023-21256 has a CVSS score of 7.8 (HIGH). This vulnerability in Android's Settings app allows attackers to launch arbitrary activities through a logic error in SettingsHomepageActivity.java. It enables local privilege escalation without requiring additional execution privileges, though user interaction is needed for exploitation. Affects Android devices running vulnerable versions of the Settings application.

📋 TL;DR

This vulnerability in Android's Settings app allows attackers to launch arbitrary activities through a logic error in SettingsHomepageActivity.java. It enables local privilege escalation without requiring additional execution privileges, though user interaction is needed for exploitation. Affects Android devices running vulnerable versions of the Settings application.

💻 Affected Systems

Products:

Android Settings application

Versions: Android versions prior to the July 2023 security patch

Operating Systems: Android

Default Config Vulnerable: ⚠️ Yes

Notes: Affects devices where the Settings app hasn't been updated with the July 2023 security patches.

📦 What is this software?

Android by Google

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⚠️ Risk & Real-World Impact

🔴

Worst Case

An attacker could gain elevated privileges on the device, potentially accessing sensitive data, installing malicious apps, or performing unauthorized actions.

🟠

Likely Case

Local attackers could bypass security restrictions to access protected settings or launch activities they shouldn't have permission to access.

🟢

If Mitigated

With proper security controls and user awareness, exploitation would be limited to specific scenarios requiring user interaction.

🌐 Internet-Facing: LOW - This is a local vulnerability requiring physical or local access to the device.

🏢 Internal Only: MEDIUM - Could be exploited by malicious apps or users with physical access to devices within an organization.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Requires user interaction and knowledge of the specific logic error to exploit successfully.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: July 2023 Android Security Patch

Vendor Advisory: https://source.android.com/security/bulletin/2023-07-01

Restart Required: Yes

Instructions:

1. Check for system updates in Settings > System > System update. 2. Install the July 2023 Android security patch. 3. Restart the device after installation.

🔧 Temporary Workarounds

Disable unnecessary app permissions

android

Restrict app permissions to minimize potential attack surface

User awareness training

all

Educate users about not interacting with suspicious prompts or unexpected Settings behavior

🧯 If You Can't Patch

Implement mobile device management (MDM) policies to restrict app installations and permissions
Monitor for unusual Settings activity or permission escalation attempts

🔍 How to Verify

Check if Vulnerable:

Check Android security patch level in Settings > About phone > Android version > Security patch level. If before July 2023, device is vulnerable.

Check Version:

adb shell getprop ro.build.version.security_patch

Verify Fix Applied:

Verify security patch level shows July 2023 or later in Settings > About phone > Android version > Security patch level.

📡 Detection & Monitoring

Log Indicators:

Unexpected activity launches from Settings app
Permission escalation attempts in system logs

Network Indicators:

Not applicable - local vulnerability

SIEM Query:

Not applicable for typical SIEM monitoring of this local Android vulnerability

📊 Metadata

CVE ID: CVE-2023-21256

CVSS v3 Score: 7.8 (HIGH)

CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

CWE: CWE-863

Published: July 13, 2023

Last Updated: November 21, 2024

🔗 References

https://android.googlesource.com/platform/packages/apps/Settings/+/62fc1d269f5e754fc8f00b6167d79c3933b4c1f4 Patch
https://source.android.com/security/bulletin/2023-07-01 Patch,Vendor Advisory
https://android.googlesource.com/platform/packages/apps/Settings/+/62fc1d269f5e754fc8f00b6167d79c3933b4c1f4 Patch
https://source.android.com/security/bulletin/2023-07-01 Patch,Vendor Advisory

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🔗 Related Vulnerabilities

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