CVE-2023-26324

Executive Summary

CVE-2023-26324 is a critical code execution vulnerability in the Xiaomi GetApps application (the official Xiaomi app store). The flaw stems from improper verification logic, allowing an attacker to bypass security checks and execute arbitrary code on the affected device. With a CVSS score of 8.8, this vulnerability poses a severe risk to user data and device integrity. No public proof-of-concept (PoC) or exploit code has been released, and no official patch has been confirmed by Xiaomi. The EPSS score of 0.0% indicates low exploitation activity in the wild, but the potential impact remains high.

CVSS Breakdown & Threat Level

• CVSS Score: 8.8 (High)
• Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
• Attack Vector: Network
• Attack Complexity: Low
• Privileges Required: None
• User Interaction: None
• Scope: Unchanged
• Confidentiality Impact: High
• Integrity Impact: High
• Availability Impact: High

Threat Level: Critical. The vulnerability can be exploited remotely without authentication or user interaction, leading to full device compromise.

Deep Dive & Mechanics

The vulnerability resides in the Xiaomi GetApps application, which is pre-installed on many Xiaomi devices. The application handles app installation and updates. The flaw is caused by a bypass in the verification logic that validates the authenticity and integrity of downloaded packages. An attacker can craft a malicious package that appears legitimate to the application, allowing arbitrary code execution with the privileges of the GetApps process.

Attack Vector:

1. Network-based: An attacker on the same network or via a man-in-the-middle (MITM) position can intercept and modify app update requests.
2. Malicious App: A malicious app already installed on the device could exploit the vulnerability to escalate privileges.

Root Cause: The verification logic does not properly validate cryptographic signatures or checksums, allowing an attacker to inject malicious code into the installation flow.

Vulnerable vs. Patched Code

No official patch or patched code is available. The vulnerable code is proprietary and not publicly disclosed. The following is a conceptual representation of the flawed verification logic:

Vulnerable Code (Conceptual):

public boolean verifyPackage(File packageFile) {
    // Bypass: No actual signature verification
    return true;
}

Patched Code (Conceptual):

public boolean verifyPackage(File packageFile) {
    // Proper signature verification
    return verifySignature(packageFile) && verifyChecksum(packageFile);
}

Exploitation & Lab Setup

Red Team

Prerequisites:

• Xiaomi device with GetApps installed (version unknown)
• Network access to the device (MITM position or co-located network)

Exploitation Steps:

1. Setup MITM Proxy: Use tools like mitmproxy or BetterCap to intercept traffic from the Xiaomi device.
2. Identify Update Requests: Monitor for requests to GetApps update endpoints.
3. Craft Malicious Package: Create a modified APK that contains malicious code but retains the original package name and version.
4. Inject Malicious Package: Replace the legitimate update response with the malicious APK.
5. Trigger Installation: The GetApps application will download and install the malicious package, executing the attacker's code.

No public exploit code is available.

Blue Team

Detection:

• Monitor network traffic for unusual APK downloads or modified responses.
• Use endpoint detection and response (EDR) tools to monitor for unexpected process execution from GetApps.
• Enable application whitelisting to prevent unauthorized installations.

Mitigation:

• Disable automatic updates in GetApps until a patch is available.
• Use a VPN to encrypt traffic and prevent MITM attacks.
• Implement network segmentation to isolate Xiaomi devices.

Indicators of Compromise (IOCs)

• Network: Unusual HTTP responses from GetApps update servers (e.g., modified APK files).
• File: Presence of unsigned or improperly signed APK files in the download cache.
• Process: GetApps process spawning unexpected child processes (e.g., shell, cmd).
• Registry/Config: Modified update URLs or disabled verification flags.

Detection Engineering

YARA Rule

rule CVE_2023_26324_GetApps_Malicious_APK {
    meta:
        description = "Detects malicious APK files exploiting CVE-2023-26324"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2023-26324"
    strings:
        $s1 = "XiaomiGetApps" nocase
        $s2 = "com.xiaomi.getapps" nocase
        $s3 = "META-INF/" nocase
        $s4 = "AndroidManifest.xml" nocase
    condition:
        all of ($s*) and filesize < 100MB
}

Sigma Rule

title: CVE-2023-26324 - Xiaomi GetApps Code Execution
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects exploitation attempts of CVE-2023-26324 via network or process anomalies
author: Valters IT
date: 2025-04-10
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith: '\GetApps.exe'
        CommandLine|contains: 'install'
    condition: selection
falsepositives:
    - Legitimate app installations
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2023-26324 - Xiaomi GetApps Malicious APK Download"; flow:to_server; content:"GET"; http_method; content:"/update"; http_uri; content:"apk"; http_uri; pcre:"/\.apk$/"; sid:1000001; rev:1;)

Remediation & Mitigation

1. Immediate: Disable automatic updates in Xiaomi GetApps settings.
2. Network: Use HTTPS inspection and certificate pinning to prevent MITM attacks.
3. Device: Monitor for suspicious app installations and review app permissions.
4. Vendor: Await an official patch from Xiaomi. Contact Xiaomi support for updates.
5. Long-term: Implement application whitelisting and use a mobile device management (MDM) solution.

Valters IT
Senior DevSecOps & Cyber Threat Intelligence Expert