# AI Experiment: Porting a PLC Exploit Takes Hours and Hundreds of Dollars

> Source: <https://dev.to/anoymask/ai-experiment-porting-a-plc-exploit-takes-hours-and-hundreds-of-dollars-56od>
> Published: 2026-09-02 04:11:55+00:00

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1. Basic Information

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**Article Title**: Experiment: Porting a PLC Exploit With AI Takes Hours and Hundreds of Dollars
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**Publisher**: SecurityWeek
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**Publication Date**: September 1, 2026
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**Source URL**: [SecurityWeek](https://www.securityweek.com/experiment-porting-a-plc-exploit-with-ai-takes-hours-and-hundreds-of-dollars/)
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**Related Source**: [Forescout Vedere Labs](https://www.forescout.com/blog/can-ai-create-plc-attacks-yes-but-it%E2%80%99s-not-that-easy-yet/)
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**Related Technologies, Products, and Datasets**: CVE-2021-31886, WAGO 750-852, WAGO 750-831 firmware V01.04.16, Nucleus FTP server, Claude Sonnet 4.6, Claude Opus 4.6, Ghidra
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**Severity**: Medium
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**Report Type**: defense_research

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2. Executive Summary

Forescout combined Claude, Ghidra, and physical hardware to port a CVE-2021-31886 exploit from the WAGO 750-852 to the 750-831 model. Achieving remote code execution (RCE) required continuous human support, 8 hours and 32 minutes, and $535.74. During C2 implant expansion, an incorrect write to flash memory permanently bricked the PLC.

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3. Defense Challenges

- Closed-source embedded PLCs without debuggers require a deep understanding of firmware-specific memory layouts and processing paths to port buffer overflows between models.
- AI-driven exploit development capabilities must be evaluated not only by success rates, but also by required human support, time, cost, and physical hardware damage.

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4. Proposed Methodology

- Feed an existing WAGO 750-852 exploit along with the 750-831 physical hardware and firmware into Claude, giving it access to a terminal, Ghidra, generated Python analysis scripts, and network tools.
- Humans correct dead ends, provide necessary disassembly context, and prompt the AI when firmware details are uncertain.

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5. Inputs

- Existing WAGO 750-852 exploit for CVE-2021-31886.
- WAGO 750-831 firmware V01.04.16 and physical hardware.
- Claude Code, Claude Sonnet 4.6 / Opus 4.6, Ghidra, terminal, and network tools.

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6. Outputs

- Pre-authentication RCE exploit for the WAGO 750-831.
- UDP payloads delivering an ICMP echo payload and the "PWNED" string.
- Records of working hours, API costs, human interventions, failures, and physical device damage.

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7. Workflow

- Analyze the existing exploit and firmware to confirm the presence of an FTP USER buffer overflow using live probing and static analysis.
- Reproduce the crash via a Denial of Service (DoS) and attempt to transition to controllable code execution.
- Have a human correct incorrect hypotheses, switch to Claude Opus 4.6, and add necessary disassembly context.
- Identify the root cause where standard FTP processing zeros out the shellcode.
- Preserve the buffer using a USER->CWD sequence and omitted CRLF, then execute the ARM shellcode.
- Generate ICMP and UDP payloads after establishing RCE, expanding into a C2 implant in a separate session.
- Record the exact point of PLC failure caused by an incorrect flash write during C2 expansion, and evaluate it as a safety limit.

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8. Evaluation Design

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**Target**: Porting a single exploit from the WAGO 750-852 to the 750-831.
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**Environment**: Closed-source firmware, no target debugger, physical PLC, FTP port 21.
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**Metrics**: Successful RCE; nature of human intervention; time for final stage; API costs; payload derivation time; physical hardware damage.
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**Comparison Boundary**: No controlled comparison against humans working alone was performed; the researchers noted that a human working alone might have been faster and cheaper.

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9. Results

- Successfully executed arbitrary ARM shellcode without authentication on the WAGO 750-831.
- The final stage required 8 hours and 32 minutes and cost $535.74.
- Created two network payloads in 12 minutes after solving target-specific buffer retention issues.
- Permanently bricked the PLC during C2 implant development due to an accidental write to flash memory.

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10. Operational Implications

- The process currently requires expert assistance and high costs, making it no easier than traditional methods.
- Payload derivation after initial RCE is fast, and improving model capabilities may lower the cost of deployment to related targets in the future.
- Even defensive AI agents can cause physical and operational impacts if they malfunction when given write access to cyber-physical systems.

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11. Success Conditions

- Access to the reference exploit, target firmware, and physical hardware.
- Human capability to supply firmware-specific disassembly and correct false hypotheses.
- An isolated lab environment capable of repeatedly observing network and memory behavior.

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12. Constraints and Limitations

- This case study covers only a single vendor, a single CVE, and a single target, and cannot be generalized.
- There is no controlled comparison against humans alone or other AI models.
- The lack of a target debugger, combined with context window limits and false hypotheses, prolonged the trial-and-error process.
- The C2 implant was never completed, as the experiment ended due to hardware destruction.

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13. Deployment and Operational Guidance

- Conduct OT exploit testing in a lab physically and network-isolated from production environments.
- Minimize network, memory, and firmware write permissions for AI agents, and establish clear stop conditions and human approval gates.
- Disable unnecessary FTP services on PLCs and block port 21 traffic from IT and external networks.
- Monitor for crashes, reboots, ICMP/UDP beacons, and configuration or firmware changes.

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14. Required Evidence and Records

- Logs of models, versions, prompts, tools, and context windows.
- Firmware hashes, physical hardware models and versions, and network topologies.
- All FTP requests, crashes, uptimes, and ICMP/UDP packet captures.
- Human interventions, time spent, token usage, and API costs.
- Memory and flash states before and after hardware destruction, alongside recovery viability.

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15. Facts / Inference / Hypothesis

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Facts

- Forescout used AI assistance to port an existing RCE exploit for the WAGO 750-852 to the 750-831, executing arbitrary ARM shellcode via a pre-authentication FTP USER buffer overflow.
- The final RCE development stage took 8 hours and 32 minutes with an API cost of $535.74, spanning multiple days with human-provided disassembly context and correction instructions.
- The issue where the FTP process cleared the shellcode was resolved by omitting the CRLF terminator and changing the sequence to USER -> CWD.
- After overcoming this barrier, Claude created two payloads—an ICMP echo and a UDP packet sending the "PWNED" string—in 12 minutes.
- During C2 implant expansion, a payload wrote to a region mapped to flash memory, permanently damaging the WAGO 750-831.

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Inference

- While AI strongly relies on expert support to solve target-specific initial exploit hurdles, it can accelerate payload derivation once code execution is established.
- OT defenders' assumption that difficult exploits represent low-reality threats must be re-evaluated as model capabilities and automation advance.

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Hypothesis

- The suggestion that marginal costs for parallel ports to similar PLCs will decrease in the future is a projection and cannot be quantified based solely on this experiment.

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16. MITRE ATT&CK Mapping

- Since this research did not observe active threat actor operations, no forced mapping is applied.

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17. Unknowns and Further Research

- Reproducibility across other vendors, CPU architectures, and firmware versions.
- Strict time and cost comparisons against humans alone, other models, and environments with or without debuggers.
- The extent to which AI agent permission constraints can prevent physical hardware damage.

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18. Impact on SOCs

In manufacturing, building automation, and water treatment environments, if legacy PLC FTP services remain reachable from IT/OT boundaries, organizations may be impacted by AI-assisted cross-model exploit porting. Organizations must map their assets, firmware, and service reachability, and ensure that AI-driven testing environments enforce physical safety, network isolation, write restrictions, and explicit stop conditions.

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19. Summary by Role

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**SOC Analysts**: Monitor for abnormal FTP USER lengths, PLC crashes, ICMP/UDP beacons, and service reachability; do not dismiss difficult exploits from threat models.
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**Administrators**: Disable and isolate unnecessary FTP services on PLCs, apply firmware updates, restrict inbound traffic from external and IT networks, and establish safety boundaries for testing hardware.
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**End Users**: This is not an attack that general users handle directly. Promptly report any abnormal PLC stoppages or suspicious network activity to maintenance personnel.
