CVE-2025-23420: OpenAtom OpenHarmony RCE Vulnerability

CVE-2025-23420 Overview

CVE-2025-23420 affects OpenHarmony v5.0.2 and prior versions. The flaw allows a local attacker to achieve arbitrary code execution in pre-installed applications through an out-of-bounds write [CWE-787]. Exploitation requires local access and low privileges, but no user interaction. OpenAtom's advisory notes the vulnerability can be exploited only in restricted scenarios, limiting practical attack surface.

The issue carries high impact to confidentiality, integrity, and availability because successful exploitation lets attackers run code within the security context of pre-installed apps. This can enable further privilege escalation or persistence on affected devices running the OpenHarmony operating system.

Critical Impact
Local attackers with low privileges can execute arbitrary code inside pre-installed OpenHarmony applications, compromising confidentiality, integrity, and availability of the device.

Affected Products

OpenAtom OpenHarmony v5.0.2
OpenAtom OpenHarmony prior versions to 5.0.2
Devices and pre-installed applications built on affected OpenHarmony releases

Discovery Timeline

2025-03-04 - CVE-2025-23420 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-23420

Vulnerability Analysis

CVE-2025-23420 is an out-of-bounds write [CWE-787] in OpenHarmony. The defect resides in code paths reachable by pre-installed apps, where a memory operation writes past the bounds of an allocated buffer. Attackers who trigger the condition can overwrite adjacent memory to corrupt program state or hijack control flow.

Because the vulnerable code executes inside pre-installed applications, successful exploitation grants code execution within those apps' trust boundaries. On OpenHarmony devices this can include access to sensitive APIs, IPC endpoints, and persisted user data. The vendor states exploitation is limited to restricted scenarios, indicating that specific preconditions must exist on the device before the attack path becomes viable.

Root Cause

The root cause is missing or insufficient bounds validation on a buffer write operation within OpenHarmony components used by pre-installed apps. When attacker-controlled input drives the write index or length, the operation writes beyond the allocated region. Refer to the OpenHarmony Security Disclosure for component-level details.

Attack Vector

The attack vector is local. An attacker must already have low-privilege code execution on the device, typically through a malicious or compromised application. No user interaction is required. The attacker then supplies crafted input to the vulnerable pre-installed app to trigger the out-of-bounds write and pivot to arbitrary code execution within that app's context.

No public proof-of-concept exploit is available at the time of publication, and the vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog.

Detection Methods for CVE-2025-23420

Indicators of Compromise

Unexpected crashes or restarts of pre-installed OpenHarmony applications, particularly with memory corruption signatures in system logs
Newly installed third-party applications requesting IPC access to pre-installed apps shortly before anomalous behavior
Unauthorized file writes or privilege changes originating from pre-installed app processes

Detection Strategies

Monitor OpenHarmony device logs (hilog) for abort signals, ASAN reports, or segmentation faults tied to pre-installed app processes
Baseline normal IPC traffic between third-party apps and pre-installed apps, then alert on deviations that could indicate exploitation attempts
Track process spawning and code execution patterns inside pre-installed applications for unexpected child processes or shell activity

Monitoring Recommendations

Centralize device telemetry from OpenHarmony fleets into a security analytics platform for correlation across devices
Alert on repeated crash-and-restart cycles in the same pre-installed application, which can indicate exploit development or brute-force attempts
Review installed application inventories on a regular cadence to identify unauthorized or side-loaded apps that could stage a local exploit

How to Mitigate CVE-2025-23420

Immediate Actions Required

Upgrade OpenHarmony devices to a version later than v5.0.2 as fixes are made available by OpenAtom
Audit installed applications and remove untrusted or side-loaded packages that could be used to reach the vulnerable code paths
Restrict installation of third-party applications on managed OpenHarmony devices through device policy

Patch Information

OpenAtom has published details of this vulnerability in the OpenHarmony Security Disclosure for March 2025. Administrators should apply the corresponding OpenHarmony release that includes the fix for CVE-2025-23420 and validate that all downstream device images incorporate the patched components.

Workarounds

Enforce application allowlisting on OpenHarmony devices to prevent untrusted apps from executing locally
Disable or restrict access to non-essential pre-installed applications where operationally feasible
Apply device management policies that block sideloading and require signed application packages

bash

# Verify installed OpenHarmony version on a device via hdc shell
hdc shell param get const.ohos.version.security_patch
hdc shell param get const.product.software.version