CVE-2025-20091 Overview
CVE-2025-20091 is a use-after-free vulnerability [CWE-416] affecting OpenHarmony v5.0.2 and prior versions. A local attacker can leverage this flaw to achieve arbitrary code execution within pre-installed applications on the device. The vulnerability requires low privileges and no user interaction, but exploitation is limited to restricted scenarios per the vendor advisory.
Critical Impact
Local attackers can execute arbitrary code inside pre-installed OpenHarmony applications, compromising confidentiality, integrity, and availability of the affected system.
Affected Products
- OpenAtom OpenHarmony v5.0.2
- OpenAtom OpenHarmony prior versions
- Devices running vulnerable OpenHarmony builds with pre-installed apps
Discovery Timeline
- 2025-03-04 - CVE-2025-20091 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-20091
Vulnerability Analysis
The vulnerability is a use-after-free condition in OpenHarmony, an open-source distributed operating system maintained by the OpenAtom Foundation. Use-after-free bugs occur when a program continues to reference memory after it has been freed. An attacker who controls the contents of the reallocated region can hijack execution flow.
In this case, the affected code path exists within logic reachable by pre-installed applications. A local attacker with the ability to interact with these apps can trigger the freed object reference and steer execution toward attacker-controlled data. The result is arbitrary code execution in the security context of the vulnerable pre-installed application.
The OpenHarmony security advisory notes that exploitation is possible only in restricted scenarios, indicating additional preconditions beyond simple local access.
Root Cause
The root cause is improper memory lifecycle management [CWE-416]. Code retains a dangling pointer to an object after that object's memory has been released. Subsequent operations on the stale pointer read or write memory that may have been reallocated for a different purpose.
Attack Vector
The attack vector is local. An attacker requires low-privileged access to the device and the ability to invoke functionality exposed by a vulnerable pre-installed application. No user interaction is required. Full technical details are documented in the OpenHarmony Security Disclosure 2025-03.
No public proof-of-concept exploit code is available at the time of publication. The vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog, and the EPSS score indicates a low probability of exploitation in the near term.
Detection Methods for CVE-2025-20091
Indicators of Compromise
- Unexpected crashes or restart events involving OpenHarmony pre-installed applications
- Anomalous memory access violations logged by the OpenHarmony kernel
- Unauthorized code execution or new child processes spawned by pre-installed apps
Detection Strategies
- Monitor process telemetry for pre-installed applications that spawn unexpected binaries or shells
- Inspect device logs for repeated segmentation faults or SIGSEGV signals tied to the same pre-installed app
- Compare installed OpenHarmony build numbers against the fixed versions listed in the OpenHarmony advisory
Monitoring Recommendations
- Centralize OpenHarmony device logs into a SIEM for correlation across the fleet
- Baseline normal behavior of pre-installed applications and alert on deviations in system call patterns
- Track vendor advisories from OpenAtom for updates to the March 2025 disclosure bulletin
How to Mitigate CVE-2025-20091
Immediate Actions Required
- Inventory all devices running OpenHarmony and identify builds at v5.0.2 or earlier
- Apply the OpenHarmony security update referenced in the OpenHarmony Security Disclosure 2025-03
- Restrict local access to affected devices while patches are being deployed
Patch Information
OpenAtom has published fixes through the OpenHarmony security disclosure process. Upgrade to a version later than v5.0.2 that includes the fix for CVE-2025-20091. Refer to the vendor advisory for the exact patched commit and release identifiers.
Workarounds
- Limit which users and processes can invoke the vulnerable pre-installed applications
- Disable or remove non-essential pre-installed apps on affected devices where operationally feasible
- Apply application sandboxing and SELinux policies to constrain the impact of successful exploitation
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
