CVE-2020-8936 Arbitrary enclave memory overwrite vulnerability in ECall ecall_restore

Medium 5.3 Published 15 Dec 2020 Updated 4 Aug 2024

An attacker can read enclave memory by exploiting a missing buffer validation in the UntrustedCall function of the Asylo library.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Local or same network only
Victim action needed: Not needed
Fix: None listed

What is CVE-2020-8936?

CVE-2020-8936 is a medium-severity memory corruption vulnerability in Google LLC Asylo, published on 15 Dec 2020. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

An arbitrary memory overwrite vulnerability in Asylo versions up to 0.6.0 allows an attacker to make a host call to UntrustedCall. UntrustedCall failed to validate the buffer range within sgx_params and allowed the host to return a pointer that was an address within the enclave memory. This allowed an attacker to read memory values from within the enclave.

Weakness: CWE-125

Which versions are affected by CVE-2020-8936?

It affects 1 product.

Products include Google Asylo.

How do I fix CVE-2020-8936?

No fix has been published for CVE-2020-8936 yet. Limit exposure of the affected software until one is available.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2020-8936 being exploited?

There is no known exploitation of CVE-2020-8936 in the wild and no public exploit code.

Sources

Also known as GHSA-mjhf-5xg4-c757.