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Assert violation

Description​

The assert! macro is used in Rust to ensure that a certain condition holds true at a certain point in your code. The assert! macro can cause the contract to panic. Therefore, the detector suggests replacing assert! constructs with Error enum structures.

Exploit Scenario​

Consider the following Soroban contract:

    pub fn assert_if_greater_than_10(_env: Env, value: u128) -> bool {
        assert!(value <= 10, "value should be less than 10");
        true
    }

The problem arises from the use of the assert! macro, if the condition is not met, the contract panics.

The vulnerable code example can be found here.

Remediation​

Avoid the use of assert! macro. Instead, use a proper error and return it.

    pub fn assert_if_greater_than_10(_env: Env, value: u128) -> Result<bool, AVError> {
        if value <= 10 {
            Ok(true)
        } else {
            Err(AVError::GreaterThan10)
        }
    }

The remediated code example can be found here.

References​