CVE-2020-8940 Unchecked buffer overrun in enc_untrusted_recvmsg
An attacker can read arbitrary memory, including secure enclave data, via an unchecked buffer overrun in Asylo's recvmsg implementation.
- 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-2020-8940?
CVE-2020-8940 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 read vulnerability in Asylo versions up to 0.6.0 allows an untrusted attacker to make a call to enc_untrusted_recvmsg using an attacker controlled result parameter. The parameter size is unchecked allowing the attacker to read memory locations outside of the intended buffer size including memory addresses within the secure enclave. We recommend upgrading or past commit fa6485c5d16a7355eab047d4a44345a73bc9131e
Which versions are affected by CVE-2020-8940?
It affects 1 product.
Products include Google Asylo.
How do I fix CVE-2020-8940?
No fix has been published for CVE-2020-8940 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-2020-8940 being exploited?
There is no known exploitation of CVE-2020-8940 in the wild and no public exploit code.
Other vulnerabilities in Google LLC Asylo
- CVE-2021-22548 Arbitrary enclave memory overread vulnerability in Asylo TrustedPrimitives::UntrustedCall
- CVE-2021-22549 Arbitrary enclave memory overwrite vulnerability in Asylo TrustedPrimitives::UntrustedCall
- CVE-2021-22550 Enclave memory overwrite/overread vulnerability in Asylo UntrustedCacheMalloc::GetBuffer
- CVE-2020-8904 Arbitrary trusted memory overwrite vulnerability in Asylo
- CVE-2021-22552 Memory overread secure enclave in Asylo 0.6.2
Sources
Also known as GHSA-8gq9-69qw-7cch.