CVE-2021-39167 : Vulnerability Insights and Analysis

OpenZepplin is a library for smart contract development with affected versions having a vulnerability in TimelockController allowing privilege escalation. Learn more details and mitigation steps here.

Understanding CVE-2021-39167

OpenZepplin library for smart contracts had a critical vulnerability in TimelockController, impacting specific versions.

What is CVE-2021-39167?

Vulnerability in TimelockController allowed an actor with the executor role to escalate privileges.
Disclosure of further details of the vulnerability is pending.

The Impact of CVE-2021-39167

CVSS Score: 10 (Critical)
Attack Vector: Network
Attack Complexity: Low
High impacts on Availability, Confidentiality, and Integrity
Privileges Required: None
Scope: Changed
No user interaction required

Technical Details of CVE-2021-39167

The technical aspects surrounding the vulnerability in OpenZeppelin Contracts.

Vulnerability Description

Improper Privilege Management (CWE-269)
Escalation of privileges through the TimelockController

Affected Systems and Versions

Affected Product: openzeppelin-contracts by OpenZeppelin
Vulnerable Versions: >=4.0.0, < 4.3.1 AND >=3.3.0, < 3.4.2 AND >= 3.3.0-solc-0.7, < 3.4.2-solc-0.7

Exploitation Mechanism

An actor with the executor role can exploit the vulnerability to escalate privileges.

Mitigation and Prevention

Steps to mitigate and prevent the vulnerabilities in OpenZeppelin Contracts.

Immediate Steps to Take

Revoke executor role from accounts not strictly controlled by the team
Ensure at least one executor and proposer remains

Long-Term Security Practices

Regularly review and audit smart contracts
Follow least privilege principle in assigning roles

Patching and Updates

Update to versions not affected by the vulnerability