CVE-2018-18920 : What You Need to Know

Py-EVM v0.2.0-alpha.33 allows attackers to exploit a vulnerability that can lead to endless execution of smart contracts without gas payment.

Understanding CVE-2018-18920

An issue in Py-EVM v0.2.0-alpha.33 allows attackers to manipulate vm.execute_bytecode calls, causing execution failures and potential endless contract execution.

What is CVE-2018-18920?

The vulnerability in Py-EVM v0.2.0-alpha.33 enables attackers to trigger computation._stack.values incorrectly, leading to execution failures due to an invalid opcode. This flaw may result in smart contracts being executed indefinitely without gas payment.

The Impact of CVE-2018-18920

The vulnerability poses a significant risk as attackers can exploit it to disrupt the normal execution of smart contracts, potentially causing financial losses and system instability.

Technical Details of CVE-2018-18920

Py-EVM v0.2.0-alpha.33 vulnerability details and affected systems.

Vulnerability Description

Attackers can initiate vm.execute_bytecode calls with manipulated input, causing computation._stack.values to deviate from expected values, resulting in execution failures.

Affected Systems and Versions

Product: Py-EVM v0.2.0-alpha.33
Vendor: N/A
Versions: N/A

Exploitation Mechanism

Attackers exploit the vulnerability by providing input that triggers computation._stack.values incorrectly, leading to execution failures.

Mitigation and Prevention

Steps to mitigate and prevent the exploitation of CVE-2018-18920.

Immediate Steps to Take

Update Py-EVM to a patched version that addresses the vulnerability.
Monitor smart contract executions for unusual behavior that may indicate exploitation.

Long-Term Security Practices

Regularly audit and review smart contracts for vulnerabilities and implement secure coding practices.
Stay informed about security updates and best practices in smart contract development.

Patching and Updates

Apply patches and updates provided by Py-EVM to fix the vulnerability and enhance system security.