CVE-2024-7510

Executive Summary

CVE-2024-7510 is a critical Use-After-Free (UAF) vulnerability in Trimble SketchUp, a widely used 3D modeling application. The flaw resides in the parsing of SKP files, where the software fails to validate the existence of an object before performing operations on it. This allows a remote attacker to execute arbitrary code in the context of the current process, provided the target user opens a malicious SKP file or visits a malicious page. The vulnerability has a CVSS score of 7.8 (High) and is currently unpatched, with no public exploit code or proof-of-concept available. The EPSS score is 0.0%, indicating low exploitation activity in the wild, but the risk remains significant due to the potential for code execution.

CVSS Breakdown & Threat Level

• CVSS Score: 7.8 (High)
• Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
• Attack Vector: Local (requires user interaction)
• Attack Complexity: Low
• Privileges Required: None
• User Interaction: Required (target must open a malicious file or page)
• Scope: Unchanged
• Confidentiality Impact: High
• Integrity Impact: High
• Availability Impact: High

Threat Level: High. The vulnerability allows full code execution with the privileges of the current user, making it a prime target for phishing campaigns and targeted attacks.

Deep Dive & Mechanics

The vulnerability is a classic Use-After-Free (CWE-416) in the SKP file parsing routine of Trimble SketchUp. When the application reads a specially crafted SKP file, it may free a memory object but retain a pointer to it. Subsequent operations on that pointer lead to dereferencing freed memory, which an attacker can exploit to execute arbitrary code.

Technical Details:

• Root Cause: Lack of validation of object existence before use.
• Trigger: Opening a malicious SKP file or visiting a malicious page that triggers file parsing.
• Exploitation: The attacker crafts an SKP file that causes a UAF condition, then uses heap spraying or other techniques to control the freed memory and redirect execution to shellcode.

Attack Scenario:

1. Attacker creates a malicious SKP file.
2. Attacker distributes the file via email, social engineering, or malicious website.
3. User opens the file in Trimble SketchUp.
4. The UAF is triggered, and arbitrary code executes in the context of the SketchUp process.

Vulnerable vs. Patched Code

Since no patch is available, a direct comparison is not possible. However, the vulnerable code likely resembles:

// Vulnerable pseudo-code
Object* obj = GetObjectFromFile();
if (obj) {
    // Use obj
    ProcessObject(obj);
    FreeObject(obj);
}
// Later, without checking if obj is still valid
UseObject(obj); // Use-After-Free

A patched version would include a null check or reference counting:

// Patched pseudo-code
Object* obj = GetObjectFromFile();
if (obj) {
    ProcessObject(obj);
    FreeObject(obj);
    obj = nullptr; // Clear pointer after free
}
// Later, check before use
if (obj) {
    UseObject(obj);
}

Exploitation & Lab Setup

Red Team

Lab Setup:

• Target: Windows 10/11 with Trimble SketchUp (any version prior to patch).
• Attacker: Kali Linux or Windows with a Python script to craft malicious SKP files.
• Tools: Python, Metasploit (for payload generation), debugger (x64dbg).

Exploitation Steps:

1. Craft Malicious SKP File: Use a fuzzer or manual analysis to identify the UAF trigger. Since no public exploit exists, this requires reverse engineering the SKP parser.
2. Generate Payload: Use msfvenom to create a reverse shell payload.
3. Heap Spray: Allocate controlled data in the freed memory region.
4. Deliver File: Send the malicious SKP via email or host on a website.
5. Execute: When the user opens the file, the UAF triggers, and the payload runs.

Example Python Snippet (Conceptual):

# This is a conceptual example; actual exploit requires reverse engineering.
import struct

def craft_malicious_skp():
    # Placeholder for UAF trigger
    payload = b"A" * 1000  # Heap spray
    # Craft SKP structure to cause UAF
    skp_data = b"\x00" * 100  # Dummy header
    skp_data += payload
    with open("malicious.skp", "wb") as f:
        f.write(skp_data)

craft_malicious_skp()

Blue Team

Detection & Response:

• Monitor for SKP file downloads from untrusted sources.
• Use endpoint detection and response (EDR) to detect unusual process behavior (e.g., SketchUp spawning cmd.exe).
• Enable ASLR and DEP to mitigate exploitation.
• Restrict execution of SketchUp in sandboxed environments.

Hunting Queries:

• Windows Event Logs: Look for Event ID 4688 (process creation) where parent process is SketchUp.exe and child is cmd.exe or powershell.exe.
• Sysmon: Monitor for network connections from SketchUp.exe to unknown IPs.

Indicators of Compromise (IOCs)

• File Hashes: (None available; will be generated when exploit is public)
• Network Indicators: Connections to attacker-controlled IPs on common ports (e.g., 4444 for Metasploit).
• Process Indicators: SketchUp.exe spawning unexpected child processes (cmd.exe, powershell.exe).
• Registry Changes: Unusual modifications to HKEY_CURRENT_USER\Software\Trimble\SketchUp.
• File System: Creation of temporary files in %TEMP% with suspicious names.

Detection Engineering

YARA Rule

rule CVE_2024_7510_SKP_UAF {
    meta:
        description = "Detects malicious SKP files exploiting CVE-2024-7510"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2024-7510"
    strings:
        $suspicious_pattern = { 00 00 00 00 00 00 00 00 } // Placeholder for UAF trigger
        $skp_magic = { 53 4B 50 } // "SKP" magic bytes
    condition:
        $skp_magic at 0 and #suspicious_pattern > 5
}

Sigma Rule

title: CVE-2024-7510 Exploitation Attempt via SKP File
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects suspicious process creation from SketchUp.exe
author: Valters IT
date: 2025-04-10
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        ParentImage|endswith: '\SketchUp.exe'
        Image|endswith:
            - '\cmd.exe'
            - '\powershell.exe'
            - '\wscript.exe'
            - '\cscript.exe'
    condition: selection
falsepositives:
    - Legitimate use of command line tools by SketchUp plugins
level: high

Suricata Rule

alert tcp $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2024-7510 - SketchUp SKP UAF Exploit Outbound Connection"; flow:to_server,established; content:"|53 4B 50|"; depth:3; classtype:attempted-user; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable SKP file parsing if not required, or use a different application for viewing SKP files.
2. Implement application whitelisting to prevent SketchUp from executing untrusted scripts.
3. Use a sandbox or virtual machine to open SKP files from untrusted sources.

Long-Term Fix:

• Monitor Trimble's advisory for a patch. Once available, apply immediately.
• Update to the latest version of SketchUp when the fix is released.
• Educate users about the risks of opening SKP files from unknown sources.

Workarounds:

• Use file reputation services (e.g., VirusTotal) to scan SKP files before opening.
• Enable Windows Defender Exploit Guard to mitigate UAF vulnerabilities.

Valters IT
Securing Digital Frontiers