CVE-2023-32274

Executive Summary

CVE-2023-32274 is a high-severity vulnerability in the Enphase Installer Toolkit Android application, version 3.27.0, involving hard-coded credentials embedded within the binary code of the application. The vulnerability allows an attacker with access to the application binary to extract embedded credentials and leverage them to gain access to sensitive information. The vulnerability carries a CVSS base score of 8.6, indicating high severity, and affects users of the Enphase Installer Toolkit Android app, which is a utility used by solar energy installers to configure and manage Enphase energy systems. With an EPSS score of 0.00571 (44.1 percentile of exploited CVEs), the vulnerability has not yet been widely exploited in the wild, but its high CVSS score suggests significant potential impact if exploited.

Technical Analysis

The Enphase Installer Toolkit Android application version 3.27.0 contains hard-coded credentials embedded directly within the application's binary code. This is a fundamental security design flaw — a class of vulnerability often referred to as "Use of Hard-coded Credentials" (a candidate for CWE-798). The credentials are statically compiled into the application as part of the source code and subsequently compiled into the DEX (Dalvik Executable) bytecode that constitutes the Android application package (APK).

The attack mechanism is straightforward: Android APK files are essentially ZIP archives that can be decompiled using freely available tools such as apktool, jadx, or dex2jar. An attacker who obtains the APK can decompile it and search the resulting decompiled source code or inspect the binary directly for embedded credential strings. These credentials, which may be API keys, database connection strings, cloud service passwords, or authentication tokens, are often stored as plain text strings and can be located using simple string-extraction utilities (e.g., strings command on the binary or grep on the decompiled source).

The attack surface extends beyond the local application. If the hard-coded credentials relate to backend services, APIs, or cloud infrastructure operated by Enphase, an attacker who extracts these credentials could potentially authenticate to those services without proper authorization. This could allow the attacker to access customer data, device configurations, installer account information, or administrative interfaces connected to Enphase's energy management ecosystem.

It is important to note that the NVD description provided does not specify the exact nature of the credentials or which systems they authenticate to. Insufficient technical detail is available regarding the specific credential type, the impacted backend service, or the extent of data exposure. The vendor, Enphase Energy, has not published a detailed technical advisory, and no official patch or fixed version has been confirmed. The only recommended action is to contact Enphase Energy support for additional information.

Exploitation Scenarios

The attack chain for CVE-2023-32274 follows the typical pattern for vulnerabilities involving hard-coded credentials in client-side applications. On the basis of the NVD description and the general vulnerability class, the following steps describe the inferred attack chain:

Step 1: Reconnaissance / Target Identification The attacker first obtains the Enphase Installer Toolkit Android application APK. This can be accomplished through several vectors: downloading the APK from official or third-party app repositories, extracting the APK from an Android device where the application is installed (using ADB backup or root access), or intercepting the APK during over-the-air distribution. The attacker then identifies the application version (3.27.0 in this case) to confirm if it is in the affected release.

Step 2: Triggering the Vulnerability Class The attacker decompiles the APK. Using standard reverse-engineering tooling, the attacker loads the APK into a decompiler (e.g., jadx, apktool) and searches the decompiled source code and resource files for string constants such as password, token, api_key, secret, or credential. The hard-coded credentials are present in plain text within the binary and are extracted without requiring any further trigger or interaction.

Step 3: Payload / Execution Method Unlike server-side vulnerabilities where a payload is injected, the "payload" in this case is the extracted credential itself. The attacker uses the extracted hard-coded credential to authenticate to the backend service or application programming interface (API) that the credential was intended to access. This may involve directly calling the backend API endpoint with the stolen credential, logging into a web portal, or authenticating to a cloud service. The specific backend endpoint or authentication mechanism is not disclosed in the NVD description, so the exact method is inferred from the vulnerability class.

Step 4: Post-exploitation Impact Once authenticated with the hard-coded credentials, the attacker gains unauthorized access to sensitive information. Given the context of Enphase Installer Toolkit (a tool used by solar installers), this sensitive information likely includes installer account data, customer site configurations, energy production data, device serial numbers, administrative functions, or potentially broader access to Enphase's cloud management backend. The attacker could potentially enumerate customers, modify device configurations, or exfiltrate sensitive operational data.

No public PoC is available for this vulnerability, and the attack chain is inferred from the vulnerability class. Specific details on which backend services were exposed by the hard-coded credentials remain undisclosed in public sources.

Impact Assessment

The business impact of CVE-2023-32274 is significant for both Enphase Energy and its customers:

Confidentiality Impact (High): The direct extraction of hard-coded credentials leads to unauthorized access to sensitive information. In the context of an installer tool, this could expose installer credentials, customer data, and system configuration details. The CVSS score of 8.6 indicates high confidentiality impact.

Integrity Impact (High): With access to the backend services, an attacker could modify device configurations, alter installer data, or manipulate system settings, leading to potential physical-world consequences in solar energy management.

Availability Impact (Low/None): The exploitation is not primarily an availability attack; however, an attacker could potentially disrupt services or lock out legitimate installers by modifying shared credentials.

Blast Radius: The affected product is the Enphase Installer Toolkit Android application version 3.27.0. This tool is used by solar panel installers who deploy Enphase IQ microinverters and related energy hardware. The blast radius includes all installers using this version, and by extension their customers whose site configurations and energy data could be accessed. The vulnerability is client-side, meaning the credential extraction can be performed by any attacker with access to the APK, making it trivially easy to exploit from a technical difficulty standpoint.

CVSS Subscore Analysis: While the CVSS vector is not provided, the base score of 8.6 corresponds to a high-severity rating. The lack of a published vector string limits detailed subscore analysis, but the overall severity indicates low attack complexity (hard-coded credentials are trivially extracted) and no user interaction required for exploitation.

Public Exploitation Status: There is no evidence of exploitation in the wild based on the EPSS percentile and the absence of the vulnerability from the CISA Known Exploited Vulnerabilities catalog.

Detection Guidance

Detection of CVE-2023-32274 is challenging because the vulnerability is static, existing within the application binary itself. Detection can be approached from two angles: (1) detecting the presence of the vulnerable APK on endpoints, and (2) detecting anomalous network activity resulting from unauthorized use of extracted credentials. The following detection rules address both angles.

Sigma Rule

title: Enphase Installer Toolkit Hard-coded Credential Use
id: 7f4c9e2a-6b3d-4c8f-9a1e-2d5b7c8d1f4a
status: experimental
description: Detects file system artifacts or process activity associated with the Enphase Installer Toolkit version 3.27.0 containing hard-coded credentials
author: Valtersit Threat Intelligence
date: 2025/01/01
logsource:
  category: process_creation
  product: windows
detection:
  selection_commandline:
    CommandLine|contains:
      - 'jadx'
      - 'apktool'
      - 'reverse'
  selection_file:
    Image|contains:
      - 'jadx'
      - 'apktool'
      - 'dex2jar'
  condition: selection_commandline or selection_file
level: medium
falsepositives:
  - Legitimate APK reverse engineering by security researchers
  - Legitimate mobile app security auditing activities

YARA Rule

rule Enphase_Installer_Toolkit_Hardcoded_Credentials
{
    meta:
        author = "Valtersit Threat Intelligence"
        description = "Detects Enphase Installer Toolkit APK containing hard-coded credentials"
        cve_id = "CVE-2023-32274"
        date = "2025-01-01"
        severity = "high"
    strings:
        $a = "com.enphase.installertoolkit" ascii wide nocase
        $b = "Enphase Installer Toolkit" ascii wide nocase
        $c = "3.27.0" ascii wide nocase
        $d = "password" ascii wide
        $e = "secret" ascii wide
        $f = "api_key" ascii wide
        $g = "token" ascii wide
    condition:
        uint16(0) == 0x4B50 and filesize < 100MB and
        2 of ($a, $b, $c) and 1 of ($d, $e, $f, $g)
}

Suricata IDS Rule

alert http any any -> any any (msg:"CVE-2023-32274 - Enphase Installer Toolkit Hard-coded Credential Exfiltration Attempt"; flow:to_server,established; content:"enphase"; http_uri; nocase; content:"api"; http_uri; nocase; content:"login"; http_uri; nocase; pcre:"/enphase.*(api|login|credential)/Ui"; sid:5000322; rev:1; metadata:cve_id "CVE-2023-32274";)

Elastic Detection

// EQL query to detect process execution of decompilation tools alongside file access to APK destined for Enphase Installer Toolkit
sequence by process.entity_id
  [process where process.name : ("jadx", "apktool", "d2j-dex2jar", "androguard") and event.action == "start"]
  [file where event.action == "read" and file.name : "*.apk" and file.path : "*enphase*"]

Splunk SPL Query

index=windows sourcetype=ProcessEvent
(CommandLine="*jadx*" OR CommandLine="*apktool*" OR CommandLine="*dex2jar*")
OR (CommandLine="*enphase*" AND CommandLine="*apk*")
| eval threat_status = if(match(CommandLine, "(?i)(jadx|apktool|dex2jar)"), "possible_cve-2023-32274_credential_extraction", "normal")
| stats count by host, user, Threat_Status, CommandLine
| where Threat_Status = "possible_cve-2023-32274_credential_extraction"

Wazuh OSSEC Rule

<group name="cve-2023-32274">
  <rule id="912762" level="12">
    <decoded_as>json</decoded_as>
    <field name="command" type="pcre2">(?i)(jadx|apktool|dex2jar|androguard)</field>
    <field name="command" type="pcre2">(?i)(enphase|installer.*toolkit|\.apk)</field>
    <description>CVE-2023-32274: Potential Enphase Installer Toolkit credential extraction attempt detected</description>
    <mitre>
      <id>T1552.001</id>
    </mitre>
    <group>credential_exfiltration,</group>
    <options>no_full_log</options>
  </rule>
</group>

Mitigation & Patch Guidance

Patch Confidence: 1/4 — PARTIAL — Workaround/mitigation only, no official fix confirmed.

As of the date of this report, no official patched version of the Enphase Installer Toolkit Android application has been confirmed by the vendor. The affected version is 3.27.0, and the vendor has directed users to contact Enphase Energy support for additional information. The absence of a confirmed fix means that all deployments of version 3.27.0 remain vulnerable until further notice.

1) Immediate Mitigations:

• Immediately reach out to Enphase Energy support at https://support.enphase.com/s/contact-us to inquire about a patched version and obtain further guidance specific to your deployment.
• Restrict the installation of the Enphase Installer Toolkit APK to trusted, managed Android devices only. Implement application whitelisting policies to prevent installation on unauthorized or unmanaged devices.
• Disable sideloading of APK files on enterprise-managed Android devices by enforcing policy controls via a Mobile Device Management (MDM) or Unified Endpoint Management (UEM) platform.
• Audit any devices where the Enphase Installer Toolkit version 3.27.0 is installed. Assume that any device that may have been in the possession of third parties (or where the APK may have been extracted) is compromised regarding the hard-coded credentials. Monitor for anomalous activity on Enphase cloud management accounts.

2) Patch / Upgrade Steps:

• Monitor Enphase Energy's official communication channels, security advisories, and the Google Play Store for an updated version of the Enphase Installer Toolkit. When a patched version is released, install it immediately across all managed devices.
• Do not install unverified builds of the application; only trust the version distributed through official channels (Google Play Store or directly from Enphase's verified distribution mechanisms).

3) Long-term Hardening:

• Enphase Energy should adopt secure credential management practices, including dynamically generated per-session tokens, OAuth-based authentication, or server-side configuration retrieval rather than embedded static credentials in client-side binaries.
• Integrate automated secrets scanning within the mobile application development lifecycle to detect hard-coded credentials during CI/CD phases.
• Enphase should implement a full rotation of all backend credentials that may have been compromised by this vulnerability; all credentials embedded in version 3.27.0 of the application must be considered publicly known and revoked.
• Enterprises using Enphase Installer Toolkit should implement network monitoring for unusual API calls or authentication patterns originating from installer accounts, especially after hours or from unexpected geolocations.
• Enphase should consider credential-monitoring services to detect illegitimate use of the extracted credentials on dark web markets or public code repositories.

References

The following references provide context and authoritative information regarding CVE-2023-32274:

1. NVD Entry for CVE-2023-32274 — https://nvd.nist.gov/vuln/detail/CVE-2023-32274 The official NVD entry, providing the CVE description, CVSS base score of 8.6, and metadata associated with this vulnerability.

2. Enphase Energy Contact Support Page — https://support.enphase.com/s/contact-us The vendor's official support contact page, which is the purported channel for obtaining additional details about the vulnerability and potential remediation.

3. Enphase Energy Official Website — https://enphase.com The vendor's main website, where security advisories or product notices regarding the Enphase Installer Toolkit may be posted in the future.

4. CWE-798: Use of Hard-coded Credentials (MITRE) — https://cwe.mitre.org/data/definitions/798.html The Common Weakness Enumeration entry corresponding to the vulnerability class described in the CNA title of this CVE.

5. FIRST.org CVSS Calculator — https://www.first.org/cvss/calculator/3.1 A resource for interpreting the CVSS 8.6 base score when the vector string becomes available.

At the time of this report, there is no published evidence of exploitation in the wild, no known threat actor campaigns leveraging this CVE, and no inclusion in the CISA Known Exploited Vulnerabilities (KEV) catalog. The EPSS score of 0.00571 (44.1 percentile) indicates a low probability of near-term exploitation, though the high CVSS score and the simplistic nature of extracting hard-coded credentials make this a high-priority item for patching and credential rotation once remediation guidance is available.