External risk intelligence

Huawei EMUI and HarmonyOS installd Module Unauthorized File Access Vulnerability

CVE advisorySeverity: CRITICAL (CVSS 9.1)

CVE-2023-39400

The vulnerability affects the installd module within mobile operating systems (EMUI and HarmonyOS). This component manages local application installation and sandboxing processes on the device itself. It is not an internet-facing service, network gateway, or remote management interface, making it inaccessible from the public internet in typical deployments.

Path Traversal

Huawei Emui

11.0.112.0.012.0.113.0.02.0.02.0.12.1.03.0.03.1.0

Halo Surface Signal: 1 out of 5 — much less likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

A parameter verification flaw in the installd module of Huawei's EMUI and HarmonyOS could allow unauthorized reading and writing of sandbox files. This vulnerability, classified as critical, is accessible over the network.

Unprotected file access in device software.
Critical flaw impacts device security controls.
Confirm relevance and exposure status.

Attack Path

How an attacker could exploit the issue

An attacker could exploit this vulnerability by sending specially crafted input to the installd module, which is responsible for handling application installations. This could allow unauthorized reading and writing of files within the sandbox, potentially leading to a compromise of sensitive data or the execution of malicious code.

No authentication or user interaction needed.
Triggered via specially crafted input to installd.
Unauthorized file read/write in sandbox.

Live Threat

Current exploitation, exposure, and threat context

This vulnerability in the installd module could allow an attacker to read and write sandbox files without authorization, potentially impacting system integrity and sensitive data.

Sandbox files and system data at risk.
Unauthorized read/write access to sandbox.
Potential for system compromise and data leakage.

Operational Fix

Recommended remediation, mitigation, and detection steps

This vulnerability in the installd module affects Huawei devices running EMUI and HarmonyOS. Identifying and verifying the presence of this affected technology on your network and determining its business criticality is the crucial first step. Once confirmed, the accountable system owner should be identified to plan for remediation, potentially coordinating with vendor updates.

System owners should manage this issue.
Verify device reachability and criticality.
Plan remediation with vendor coordination.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

Free EASM Trial See How Signal Works

Frequently asked questions

What is the Huawei installd module?

The installd module is a core component within Huawei's EMUI and HarmonyOS operating systems. It functions as an internal system service responsible for managing the installation lifecycle of applications and enforcing the security boundaries, or sandboxes, that keep app data isolated from one another and the rest of the system.

What does CWE-22 and CWE-285 mean for CVE-2023-39400?

These codes identify weaknesses in how the software handles file paths and verifies permissions. In this context, they mean the module fails to properly validate inputs or check if a user is authorized to perform a specific file action. Consequently, an attacker can bypass these security checks to read or modify files that should have been locked inside an application's private sandbox.

How can an attacker trigger this vulnerability?

The vulnerability is triggered by sending specially crafted input to the installd module. Because the flaw lies in parameter verification, the module processes this malicious data as if it were legitimate. It is important to note that this does not require the attacker to have pre-existing authentication or involve any user interaction to initiate the unauthorized file operations.

Is this vulnerability reachable from the internet?

According to Halo Surface Signal, this is highly unlikely. While the CVE is classified as network-accessible, the affected installd module operates locally on the device to manage internal processes. It does not function as an internet-facing service or a remote gateway, meaning an attacker generally cannot reach this component directly from the public internet.

What steps should I take if I use Huawei devices?

Begin by creating an inventory of devices running the affected versions of EMUI or HarmonyOS. Once identified, work with the relevant system owners to assess their business role and look for official security updates from Huawei. Coordinating these updates is the primary way to patch the underlying logic flaw within the installd module.

References

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.