Forescout Uses Claude to Port WAGO PLC Exploit, Bricking Device in C2 Test
Summary
Forescout researchers used Claude Code to port a CVE-2021-31886-based RCE exploit from a WAGO 750-852 to a 750-831, requiring extensive oversight and over $500 for the final RCE stage; a C2 follow-up permanently bricked the PLC.
Key points
- The starting exploit targeted a WAGO 750-852 and used CVE-2021-31886, a pre-authentication buffer overflow in the Nucleus FTP server that enables arbitrary ARM shellcode execution.
- Researchers attempted to adapt the exploit to a WAGO 750-831 using Claude Code with terminal access, reference files, Ghidra, and the physical PLC.
- Claude confirmed the flaw through live probing and static firmware analysis, then generated a payload that crashed the PLC; researchers had to redirect the AI through incorrect leads before achieving controlled execution.
- After switching from Claude Sonnet 4.6 to Claude Opus 4.6 and directing it to ask for help when uncertain, the AI identified why injected code was being erased and produced two working payloads within 12 minutes.
- The final RCE-development stage used over $500 in API calls across a session lasting more than eight hours.
- In a follow-up attempt to create a C2 implant, a complex payload wrote to a region mapped to flash memory and permanently bricked the PLC.
- Forescout said a researcher could currently port the exploit faster and more cheaply without AI, but noted that declining expert-intervention needs could make AI-assisted work easier to scale across related targets.
Article Details
- Attack Vectors
- CVE-2021-31886 is a pre-authentication buffer overflow in the Nucleus FTP server. The article says it can allow unauthenticated arbitrary ARM shellcode execution on a WAGO 750-852 PLC.
- Forescout researchers ported the exploit to a WAGO 750-831 PLC. The experiment achieved controlled code execution after extensive researcher oversight.
- A follow-up attempt to develop a command-and-control implant used increasingly complex payloads; one wrote to a region mapped to flash memory and permanently bricked the PLC.
MITRE ATT&CK
CVE
Vendors
AnthropicResearchers at Forescout’s Vedere Labs used Anthropic’s Claude to port a working remote code execution (RCE) exploit from one WAGO programmable logic controller (PLC) to another.WAGOResearchers at Forescout’s Vedere Labs used Anthropic’s Claude to port a working remote code execution (RCE) exploit from one WAGO programmable logic controller (PLC) to another.
Products
Claude Opus 4.6Progress stalled until the team switched from Claude Sonnet 4.6 to Claude Opus 4.6 and instructed the model to ask for help whenever it was uncertain about a firmware detail.Claude Sonnet 4.6Progress stalled until the team switched from Claude Sonnet 4.6 to Claude Opus 4.6 and instructed the model to ask for help whenever it was uncertain about a firmware detail.WAGO 750-831experiment, Forescout researchers set out to adapt that exploit to a related but distinct model, the WAGO 750-831, and to see whether the AI could then push the result further into a full command-and-control implant.WAGO 750-852The starting point was a previously developed exploit for the WAGO 750-852 PLC, based on CVE-2021-31886, a pre-authentication buffer overflow in the Nucleus FTP server that allows an unauthenticated attacker to execute
Tools
Claude CodeThe researchers used Claude Code, giving it access to a terminal, reference files, the reverse-engineering tool Ghidra, and the physical target device.GhidraThe researchers used Claude Code, giving it access to a terminal, reference files, the reverse-engineering tool Ghidra, and the physical target device.