CVE-2024-20742: Adobe Substance 3D Painter RCE Flaw

CVE-2024-20742 Overview

CVE-2024-20742 is an out-of-bounds read vulnerability in Adobe Substance 3D Painter versions 9.1.1 and earlier. The flaw occurs when the application parses a crafted file, causing a read past the end of an allocated memory structure. An attacker can leverage this condition to execute code in the context of the current user. Exploitation requires user interaction: a victim must open a malicious file supplied by the attacker.

Critical Impact
Successful exploitation grants arbitrary code execution as the logged-in user, potentially enabling malware installation, credential theft, or lateral movement from workstations used by 3D artists and designers.

Affected Products

Adobe Substance 3D Painter 9.1.1
Adobe Substance 3D Painter versions prior to 9.1.1
All supported platforms running vulnerable Substance 3D Painter builds

Discovery Timeline

2024-02-15 - CVE-2024-20742 published to the National Vulnerability Database
2024-02-15 - Adobe releases security bulletin APSB24-04
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2024-20742

Vulnerability Analysis

The vulnerability is classified as an out-of-bounds read [CWE-125]. Substance 3D Painter reads data beyond the boundaries of an allocated memory structure while parsing a specially crafted file. The condition arises because file-format parsing routines fail to validate length or offset fields against the actual size of the allocated buffer.

Out-of-bounds reads can disclose adjacent memory contents and, when combined with attacker-controlled data placement, corrupt program state used for indirect control flow. Adobe rates this issue as enabling arbitrary code execution in the context of the current user. The attack complexity is low and no privileges are required, but the attacker must convince a user to open a malicious project or asset file.

Root Cause

The root cause is insufficient bounds checking during file parsing. When Substance 3D Painter processes a crafted input file, the parser trusts embedded size or index values without validating that the requested read stays within the bounds of the allocated structure. The resulting read past the buffer boundary can expose sensitive process memory or influence subsequent object handling, enabling code execution paths.

Attack Vector

Exploitation requires local access with user interaction. An attacker crafts a malicious Substance 3D asset or project file and delivers it through phishing, watering-hole sites, shared asset libraries, or supply-chain compromise of 3D content marketplaces. When the victim opens the file in Substance 3D Painter, the malformed structure triggers the out-of-bounds read and the exploitation chain that leads to code execution under the user's account.

No public proof-of-concept exploit is available and the vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog. Refer to the Adobe security bulletin APSB24-04 for vendor-provided technical context.

Detection Methods for CVE-2024-20742

Indicators of Compromise

Unexpected Substance 3D Painter process crashes or hangs correlated with opening files received via email, chat, or downloaded from untrusted sources
Child processes spawned by Substance 3D Painter.exe such as cmd.exe, powershell.exe, or rundll32.exe
Outbound network connections initiated by the Substance 3D Painter process to previously unseen hosts shortly after a file open event
Substance 3D project or asset files delivered from external senders with abnormal size, structure, or extensions

Detection Strategies

Monitor process creation events where Substance 3D Painter is the parent of shell interpreters or scripting engines
Alert on Substance 3D Painter reading files from user download directories immediately followed by writes to autostart locations or the user profile
Track loading of unsigned or unusual DLLs into the Substance 3D Painter process
Correlate crash telemetry from Substance 3D Painter with file-open events to surface parser-triggered anomalies

Monitoring Recommendations

Enable and forward endpoint process, file, and network telemetry to a centralized analytics platform for 3D content creation workstations
Baseline normal Substance 3D Painter behavior to identify deviations such as unexpected memory allocations or module loads
Log downloads of .spp, .sbs, .sbsar, and related Substance file types from external sources for retrospective hunting

How to Mitigate CVE-2024-20742

Immediate Actions Required

Upgrade Adobe Substance 3D Painter to a version later than 9.1.1 as directed in Adobe security bulletin APSB24-04
Inventory all workstations with Substance 3D Painter installed and prioritize patching for artists who receive external files
Instruct users to open Substance 3D files only from trusted sources and to verify provenance before opening third-party assets
Restrict user privileges so that exploitation of a user-context code execution flaw yields the minimum possible impact

Patch Information

Adobe addressed CVE-2024-20742 in the update described by Adobe Security Bulletin APSB24-04. Apply the fixed release published by Adobe to remediate the out-of-bounds read. Verify installed versions across managed endpoints after deployment to confirm the vulnerable builds are no longer present.

Workarounds

Block delivery of Substance 3D project and asset files from untrusted external senders at the email gateway
Use application allow-listing to prevent unpatched Substance 3D Painter installations from launching until updates are applied
Isolate 3D content workstations on segmented networks to limit lateral movement if a workstation is compromised
Disable file associations that automatically open Substance 3D files from browsers or messaging clients

bash

# Example: enumerate installed Substance 3D Painter versions on Windows endpoints
Get-ItemProperty "HKLM:\Software\Microsoft\Windows\CurrentVersion\Uninstall\*" |
  Where-Object { $_.DisplayName -like "*Substance 3D Painter*" } |
  Select-Object DisplayName, DisplayVersion, InstallLocation