CVE-2024-11579

Executive Summary

CVE-2024-11579 is a critical out-of-bounds write vulnerability in Luxion KeyShot, a professional 3D rendering and animation application. The flaw resides in the parsing of OBJ files, where insufficient validation of user-supplied data allows an attacker to write past the end of an allocated buffer. Successful exploitation requires user interaction—the victim must open a malicious OBJ file or visit a malicious page that triggers the parsing. An attacker can achieve remote code execution in the context of the current process, leading to full compromise of the affected system. The vulnerability was reported via the Zero Day Initiative (ZDI-CAN-23697) and currently has no known patch or public exploit code. The EPSS score is 0.0%, indicating low exploitation likelihood in the wild, but the severity (CVSS 7.8) demands immediate attention for organizations using KeyShot.

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 to open a file)
• Attack Complexity: Low
• Privileges Required: None
• User Interaction: Required (victim must open malicious OBJ)
• Scope: Unchanged
• Confidentiality Impact: High
• Integrity Impact: High
• Availability Impact: High
• Threat Level: High – Remote code execution with low complexity, though user interaction limits mass exploitation.

Deep Dive & Mechanics

The vulnerability is a classic out-of-bounds write (CWE-787) in Luxion KeyShot’s OBJ file parser. OBJ files are text-based 3D geometry definitions that include vertex coordinates, normals, texture coordinates, and face indices. The parser allocates a buffer for vertex data but fails to validate the number of vertices or indices provided in the file. By crafting an OBJ file with an excessive number of vertices or malformed index values, an attacker can trigger a write beyond the allocated buffer boundary. This overwrites adjacent memory regions, potentially corrupting function pointers, return addresses, or other critical data structures. The result is arbitrary code execution within the KeyShot process, which runs with the privileges of the current user. The vulnerability is triggered during the parsing phase, before any rendering occurs, making it a reliable entry point for exploitation.

Vulnerable vs. Patched Code

Since no official patch is available, a direct code comparison is not possible. However, the vulnerable code pattern is typical of C/C++ applications that use fixed-size buffers without bounds checking:

Vulnerable (pseudocode):

void parse_OBJ_vertices(char* file_data) {
    char vertex_buffer[1024]; // Fixed-size buffer
    int index = 0;
    while (parse_next_vertex(file_data, &vertex)) {
        vertex_buffer[index++] = vertex; // No bounds check
    }
}

Patched (pseudocode):

void parse_OBJ_vertices(char* file_data) {
    int max_vertices = 1024;
    char* vertex_buffer = malloc(max_vertices * sizeof(vertex_t));
    int index = 0;
    while (parse_next_vertex(file_data, &vertex)) {
        if (index >= max_vertices) {
            max_vertices *= 2;
            vertex_buffer = realloc(vertex_buffer, max_vertices * sizeof(vertex_t));
        }
        vertex_buffer[index++] = vertex;
    }
    free(vertex_buffer);
}

The patched version uses dynamic memory allocation with reallocation and bounds checking, preventing out-of-bounds writes.

Exploitation & Lab Setup

Red Team (Exploitation)

Lab Setup:

• Target: Windows 10/11 with Luxion KeyShot (any version prior to patch)
• Attacker: Kali Linux or any system with a text editor and Python
• Tools: Python 3, Metasploit (optional), custom OBJ generator

Exploitation Steps:

1. Craft Malicious OBJ File: Create an OBJ file with an excessive number of vertex definitions (e.g., 10,000+ vertices) or malformed face indices that cause out-of-bounds writes.

   # exploit_generator.py
   with open('malicious.obj', 'w') as f:
       f.write("# Malicious OBJ for CVE-2024-11579\n")
       for i in range(10000):
           f.write(f"v {i} {i} {i}\n")
       f.write("f 1 2 3\n")
   

2. Deliver File: Send the malicious OBJ file via email, download link, or USB drive.
3. Trigger Exploit: Victim opens the file in KeyShot. The parser crashes or executes shellcode.
4. Achieve Code Execution: If the write overwrites a return address or function pointer, redirect execution to attacker-controlled shellcode (e.g., reverse shell).

Note: No public exploit code is available; this is a conceptual approach.

Blue Team (Defense)

Detection & Prevention:

• User Awareness: Train users not to open OBJ files from untrusted sources.
• Application Control: Use AppLocker or WDAC to restrict KeyShot execution to trusted contexts.
• Sandboxing: Run KeyShot in a sandboxed environment (e.g., Windows Sandbox, Firejail) to limit impact.
• Memory Protection: Enable ASLR, DEP, and CFG on the system.
• File Scanning: Use antivirus/EDR to scan OBJ files for anomalies (e.g., excessive vertex counts).

Indicators of Compromise (IOCs)

• File Hashes (SHA-256): (Example – replace with actual if discovered)
  • malicious.obj: e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855
• Network Indicators: Outbound connections from KeyShot process to unknown IPs (if shellcode connects back).
• Process Anomalies: KeyShot.exe crashing or exhibiting unusual memory access patterns.
• Registry/File System: Unusual files in %TEMP% or %APPDATA% created by KeyShot.

Detection Engineering

YARA Rule

rule CVE_2024_11579_OBJ_Exploit {
    meta:
        description = "Detects malicious OBJ files targeting CVE-2024-11579"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2024-11579"
    strings:
        $obj_header = "v " ascii
        $excessive_vertices = /v\s+\d+\s+\d+\s+\d+/  // Matches vertex lines
    condition:
        $obj_header and #excessive_vertices > 5000  // Threshold for suspicious count
}

Sigma Rule

title: Suspicious OBJ File with Excessive Vertices
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects opening of OBJ files with an abnormally high number of vertices, indicative of CVE-2024-11579 exploitation.
author: Valters IT
date: 2025-04-10
logsource:
    category: file_event
    product: windows
detection:
    selection:
        Image|endswith: '\KeyShot.exe'
        TargetFilename|endswith: '.obj'
    condition: selection
falsepositives:
    - Legitimate large 3D models
level: high

Suricata Rule

alert tcp $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2024-11579 Potential OBJ Exploit Download"; flow:to_server,established; content:"|76 20|"; depth:2; byte_test:2,>,5000,0; classtype:attempted-user; sid:1000001; rev:1;)

Remediation & Mitigation

• Immediate: Discontinue use of Luxion KeyShot until a patch is released. If unavoidable, restrict file opening to trusted sources only.
• Short-term: Implement application whitelisting and run KeyShot in a sandboxed environment.
• Long-term: Monitor Luxion’s advisory channels for an official patch. Apply it as soon as available.
• Compensating Controls: Use endpoint detection and response (EDR) to monitor for anomalous KeyShot behavior. Enable Windows Defender Exploit Guard (CFG, DEP, ASLR).

Valters IT
Senior DevSecOps & Cyber Threat Intelligence Analyst