CVE-2023-51435

Executive Summary

CVE-2023-51435 is a vulnerability affecting certain Honor products, characterized by an incorrect privilege assignment. Successful exploitation of this flaw could lead to information leakage, potentially exposing sensitive data to unauthorized local users. The vulnerability has a CVSS score of 7.1, indicating a high severity. The exact affected versions and patch status remain unknown, and no public proof-of-concept (PoC) or exploit code is available at this time. The vulnerability is classified under CWE-266 (Incorrect Privilege Assignment) and is associated with MITRE ATT&CK tactic T1190 (Exploit Public-Facing Application), though local access is required.

CVSS Breakdown & Threat Level

• CVSS Score: 7.1 (High)
• Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:L
• Attack Vector (AV): Local (L) – The attacker must have local access to the device.
• Attack Complexity (AC): Low (L) – No special conditions are required for exploitation.
• Privileges Required (PR): Low (L) – The attacker needs low-level privileges.
• User Interaction (UI): None (N) – No user action is required.
• Scope (S): Unchanged (U) – The vulnerability does not affect other components.
• Confidentiality (C): High (H) – Significant information disclosure is possible.
• Integrity (I): Low (L) – Limited ability to modify data.
• Availability (A): Low (L) – Limited impact on system availability.

Threat Level: High. The vulnerability allows local privilege escalation leading to information leakage, which can be a stepping stone for further attacks.

Deep Dive & Mechanics

The vulnerability stems from incorrect privilege assignment within Honor products. This means that the system does not properly enforce access controls, allowing a low-privileged local user to access resources or data that should be restricted. The exact mechanism is not publicly detailed, but it likely involves improper handling of permissions for system files, processes, or inter-process communication (IPC) channels.

Attack Scenario:

1. An attacker gains local access to an Honor device (e.g., via a malicious app or physical access).
2. The attacker exploits the incorrect privilege assignment to read sensitive data (e.g., credentials, personal information, system logs).
3. The attacker exfiltrates the data or uses it for further privilege escalation.

Vulnerable vs. Patched Code

Since no patch details or code snippets are available, a direct comparison cannot be made. However, the fix would typically involve:

• Implementing proper access control checks before granting access to sensitive resources.
• Using mandatory access control (MAC) mechanisms like SELinux or AppArmor.
• Reviewing and correcting permission settings for files, directories, and system services.

Exploitation & Lab Setup

Red Team

Objective: Demonstrate local information leakage.

Prerequisites:

• An Honor device running a vulnerable firmware version.
• Low-privileged shell access (e.g., via ADB or a malicious app).

Steps:

1. Identify sensitive files or resources accessible due to incorrect privileges.

   find / -type f -perm -o+r 2>/dev/null | grep -E "(password|key|token|config)"
   

2. Attempt to read protected system files.

   cat /data/system/packages.xml
   

3. If successful, exfiltrate the data.

Note: No public exploit code is available. The above is a generic approach.

Blue Team

Detection:

• Monitor for unusual file access patterns by low-privileged processes.
• Use auditd to log access to sensitive files.
• Implement file integrity monitoring (FIM) on critical system files.

Prevention:

• Apply the latest firmware updates from Honor.
• Restrict local access to trusted users only.
• Use application sandboxing and least privilege principles.

Indicators of Compromise (IOCs)

• File Access Logs: Unauthorized access to /data/system/packages.xml, /data/misc/wifi/wpa_supplicant.conf, or similar sensitive files.
• Process Anomalies: A low-privileged process attempting to read files owned by root or system.
• Network Connections: Unexpected outbound connections from a local process to an external IP (data exfiltration).

Detection Engineering

YARA Rule

rule CVE_2023_51435_InfoLeak {
    meta:
        description = "Detects attempts to access sensitive files due to incorrect privilege assignment on Honor devices"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2023-51435"
    strings:
        $sensitive_path1 = "/data/system/packages.xml"
        $sensitive_path2 = "/data/misc/wifi/wpa_supplicant.conf"
        $sensitive_path3 = "/data/system/users/0/accounts.db"
    condition:
        any of ($sensitive_path*) and uint16(0) == 0x5a4d // MZ header for PE files (example)
}

Sigma Rule

title: CVE-2023-51435 - Incorrect Privilege Assignment on Honor Devices
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects unauthorized access to sensitive files by low-privileged processes
author: Valters IT
date: 2025-04-10
references:
    - https://nvd.nist.gov/vuln/detail/CVE-2023-51435
logsource:
    product: linux
    service: auditd
detection:
    selection:
        type: 'SYSCALL'
        syscall: 'open'
        key: 'sensitive_files'
        uid: '>=1000'  # Non-root users
        file.name:
            - '/data/system/packages.xml'
            - '/data/misc/wifi/wpa_supplicant.conf'
            - '/data/system/users/0/accounts.db'
    condition: selection
falsepositives:
    - Legitimate system processes running as non-root
level: high

Suricata Rule

alert tcp $HOME_NET any -> $EXTERNAL_NET $HTTP_PORTS (
    msg:"CVE-2023-51435 - Potential Data Exfiltration from Honor Device";
    flow:to_server,established;
    content:"POST"; http_method;
    content:"/upload"; http_uri;
    pcre:"/sensitive_data|password|token/i";
    sid:1000001;
    rev:1;
    reference:cve,2023-51435;
    classtype:attempted-recon;
    priority:2;
)

Remediation & Mitigation

• Patch: Honor has not released a public patch. Contact Honor support for updates.
• Workaround: Restrict local access to trusted users. Use application sandboxing.
• Monitoring: Implement the detection rules above to identify exploitation attempts.
• Hardening: Apply the principle of least privilege to all system processes and users.

Valters IT