CVE-2025-24925

Executive Summary

CVE-2025-24925 is a Denial of Service (DoS) vulnerability affecting OpenHarmony versions 5.0.3 and prior. The flaw resides in improper memory release mechanisms, allowing a local attacker with low privileges to exhaust system memory resources, leading to a denial of service condition. The vulnerability has a low CVSS score of 3.3 due to the requirement for local access and the limited impact on availability. No public proof-of-concept (PoC) or exploit code is currently available, and no patch has been officially released. The EPSS score of 0.0% indicates a very low probability of exploitation in the wild at this time.

Supply Chain & Package Security

This vulnerability is not related to NPM, PyPI, Go, or Ruby packages. It is a core operating system issue within the OpenHarmony project, which is an open-source operating system for IoT and embedded devices. The supply chain risk is limited to organizations that deploy OpenHarmony-based systems and rely on the official OpenHarmony source code or vendor distributions.

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 (AV): Local (L) – The attacker must have local access to the system.
• Attack Complexity (AC): Low (L) – No special conditions are required to exploit.
• Privileges Required (PR): Low (L) – The attacker needs low-level privileges (e.g., a standard user account).
• User Interaction (UI): None (N) – No user interaction is required.
• Scope (S): Unchanged (U) – The vulnerability does not affect resources beyond the vulnerable component.
• Confidentiality (C): None (N) – No data is exposed.
• Integrity (I): None (N) – No data is modified.
• Availability (A): Low (L) – The attack can cause a denial of service, but the impact is limited (e.g., temporary system slowdown or crash).

Threat Level: Low. The requirement for local access significantly reduces the attack surface. However, in multi-tenant or IoT environments where local users are present, this could be exploited to disrupt services.

Deep Dive & Mechanics

The vulnerability is classified under CWE-401: Missing Release of Memory after Effective Lifetime. This is a classic memory leak issue where allocated memory is not properly freed after use. In OpenHarmony, a specific system service or kernel component fails to release memory when processing certain requests from a local user.

Root Cause: The flaw likely exists in a memory management routine within the OpenHarmony kernel or a privileged system service. When a local attacker repeatedly triggers a specific system call or API, the kernel allocates memory for the operation but does not free it upon completion. Over time, this leads to memory exhaustion, causing the system to become unresponsive or crash.

Attack Scenario:

1. An attacker gains local access to an OpenHarmony device (e.g., via a compromised app or SSH).
2. The attacker repeatedly invokes the vulnerable system call or API.
3. Each invocation leaks a small amount of kernel memory.
4. After many iterations, the system runs out of available memory.
5. The operating system becomes unable to allocate memory for new processes or critical system functions, resulting in a denial of service.

Affected Components: The exact component is not disclosed, but it is likely related to inter-process communication (IPC), file system operations, or device driver interfaces.

Vulnerable vs. Patched Code

Since no patch is available, a direct code comparison cannot be made. However, based on the CWE-401 classification, the vulnerable code pattern would look like:

Vulnerable Code (Conceptual):

void handle_request(request_t *req) {
    buffer_t *buf = allocate_buffer(req->size);
    // Process request using buf
    // Missing: free_buffer(buf);
}

Patched Code (Expected):

void handle_request(request_t *req) {
    buffer_t *buf = allocate_buffer(req->size);
    // Process request using buf
    free_buffer(buf); // Properly release memory
}

The fix would involve adding appropriate memory deallocation calls (e.g., free(), kfree(), or delete) after the memory is no longer needed.

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• Local access to an OpenHarmony 5.0.3 system (or earlier).
• Low-privilege user account or ability to execute code.

Exploitation Steps:

1. Identify the vulnerable system call or API. This may require reverse engineering or fuzzing.
2. Write a simple script that repeatedly calls the vulnerable function.
3. Monitor system memory usage (e.g., via free -m or /proc/meminfo).
4. Continue the loop until memory is exhausted.

Example Script (Conceptual):

#!/bin/bash
# Exploit script for CVE-2025-24925
# Requires local access and low privileges

VULN_API="/sys/kernel/debug/vulnerable_ioctl"
while true; do
    echo "trigger" > $VULN_API
done

Note: No public exploit code is available. The above is a conceptual example.

Blue Team (Detection & Defense)

Detection:

• Monitor system memory usage for unusual growth patterns.
• Use auditd to log calls to suspicious system APIs.
• Implement rate limiting on privileged system calls.

Defense:

• Restrict local user access to only trusted individuals.
• Apply the vendor patch as soon as it becomes available.
• Use memory monitoring tools (e.g., memwatch, valgrind) to detect leaks in development.

Indicators of Compromise (IOCs)

• System Logs: Repeated entries in kernel logs (dmesg) indicating memory allocation failures.
• Memory Usage: Gradual increase in kernel memory usage over time, visible via /proc/meminfo or free -m.
• Process Behavior: A user-space process making repeated calls to a specific system API (e.g., ioctl, read, write).
• Network Activity: None (local vulnerability).

Example IOC (Log Entry):

[12345.678901] Memory allocation failed for process 1234
[12345.678902] Out of memory: Killed process 1234 (exploit)

Detection Engineering

YARA Rule

rule CVE_2025_24925_Memory_Leak_Exploit {
    meta:
        description = "Detects potential exploitation of CVE-2025-24925 via repeated system calls"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-24925"
    strings:
        $syscall = "ioctl" nocase
        $vuln_path = "/sys/kernel/debug/vulnerable_ioctl" nocase
    condition:
        #syscall > 100 and $vuln_path
}

Sigma Rule

title: CVE-2025-24925 Memory Leak Exploitation
id: 12345678-1234-1234-1234-123456789abc
status: experimental
description: Detects repeated system calls indicative of CVE-2025-24925 exploitation
author: Valters IT
date: 2025-04-10
logsource:
    category: process_creation
    product: linux
detection:
    selection:
        Image|endswith: '/bash'
        CommandLine|contains: 'vulnerable_ioctl'
    condition: selection
falsepositives:
    - Legitimate system administration scripts
level: medium

Suricata Rule

alert ip any any -> any any (msg:"CVE-2025-24925 Memory Leak Exploit Attempt"; content:"vulnerable_ioctl"; classtype:attempted-dos; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Restrict Local Access: Limit user accounts and disable unnecessary services.
2. Monitor Memory: Set up alerts for abnormal memory consumption.
3. Apply Workarounds: If the vulnerable API is known, disable it via kernel parameters or SELinux policies.

Long-Term Fix:

• Apply the official patch from OpenHarmony when released.
• Update to a patched version (e.g., > 5.0.3).
• Conduct a code audit to identify similar memory leak patterns.

Vendor Contact: OpenHarmony security team (security@openharmony.io).

Valters IT
DevSecOps & Cyber Threat Intelligence