CVE-2020-8940 : What You Need to Know

An arbitrary memory read vulnerability in Asylo versions up to 0.6.0 allows an untrusted attacker to exploit the enc_untrusted_recvmsg function, potentially leading to memory disclosure within secure enclaves.

Understanding CVE-2020-8940

This CVE involves an unchecked buffer overrun in the enc_untrusted_recvmsg function in Asylo versions up to 0.6.0.

What is CVE-2020-8940?

This vulnerability allows an untrusted attacker to manipulate a specific parameter, leading to unauthorized memory access beyond the intended buffer size, including memory within secure enclaves.

The Impact of CVE-2020-8940

The vulnerability poses a medium-severity risk with high confidentiality impact, potentially allowing attackers to read sensitive information from memory.

Technical Details of CVE-2020-8940

This section provides more in-depth technical insights into the vulnerability.

Vulnerability Description

The vulnerability arises from an unchecked parameter size in the enc_untrusted_recvmsg function, enabling attackers to read memory locations outside the intended buffer size.

Affected Systems and Versions

Product: Asylo
Vendor: Google LLC
Versions affected: Up to 0.6.0

Exploitation Mechanism

Attackers can exploit this vulnerability by manipulating the result parameter in the enc_untrusted_recvmsg function, allowing unauthorized memory access.

Mitigation and Prevention

To address CVE-2020-8940, immediate actions and long-term security practices are recommended.

Immediate Steps to Take

Upgrade Asylo to a version beyond 0.6.0 or apply commit fa6485c5d16a7355eab047d4a44345a73bc9131e.

Long-Term Security Practices

Regularly update software to the latest versions.
Implement secure coding practices to prevent buffer overflows.

Patching and Updates

Apply the recommended upgrade or commit to mitigate the vulnerability.