CVE-2021-36219 : Exploit Details and Defense Strategies

An issue was discovered in SKALE sgxwallet 1.58.3 where the input for ECALL 14 triggers a branch that frees a non-initialized pointer from the stack. An attacker can exploit this to compromise the enclave's integrity. This vulnerability was fixed after version 1.58.3 and is not present in sgxwallet v1.77.0.

Understanding CVE-2021-36219

This section provides insights into the vulnerability and its impact.

What is CVE-2021-36219?

CVE-2021-36219 is a security flaw in SKALE sgxwallet 1.58.3 that allows an attacker to manipulate enclave calls, leading to the compromise of enclave integrity.

The Impact of CVE-2021-36219

The vulnerability enables attackers to prepare a stack with a valid address and then free it, resulting in the compromise of enclave integrity.

Technical Details of CVE-2021-36219

Explore the specifics of the vulnerability in this section.

Vulnerability Description

The flaw arises from freeing a non-initialized pointer when processing ECALL 14 input, allowing attackers to compromise enclave integrity.

Affected Systems and Versions

SKALE sgxwallet 1.58.3 is affected, while the issue is resolved in version v1.77.0.

Exploitation Mechanism

Attackers can chain multiple enclave calls to create a stack with a valid address, which can be freed to compromise enclave integrity.

Mitigation and Prevention

Discover how to protect your systems from CVE-2021-36219 in this section.

Immediate Steps to Take

Ensure you have updated sgxwallet to version v1.77.0 to eliminate the vulnerability and enhance enclave security.

Long-Term Security Practices

Implement secure coding practices and perform regular security audits to prevent similar vulnerabilities.

Patching and Updates

Stay informed about security patches and updates for sgxwallet to mitigate potential risks.