CVE-2020-8912 In-band key negotiation issue in AWS S3 Crypto SDK for GoLang
An attacker with write access can downgrade encryption to reveal authentication keys, allowing decryption of sensitive data in S3 buckets.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2020-8912?
CVE-2020-8912 is a low-severity vulnerability in Google LLC AWS S3 Crypto SDK for GoLang, published on 11 Aug 2020. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
A vulnerability in the in-band key negotiation exists in the AWS S3 Crypto SDK for GoLang versions prior to V2. An attacker with write access to the targeted bucket can change the encryption algorithm of an object in the bucket, which can then allow them to change AES-GCM to AES-CTR. Using this in combination with a decryption oracle can reveal the authentication key used by AES-GCM as decrypting the GMAC tag leaves the authentication key recoverable as an algebraic equation. It is recommended to update your SDK to V2 or later, and re-encrypt your files.
Weakness: CWE-327
Which versions are affected by CVE-2020-8912?
3 open source packages ship an affected version, including github.com/aws/aws-sdk-go. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
github.com/aws/aws-sdk-go Go | All versions | None |
github.com/aws/aws-sdk-go Go | All versions | 1.34.0 |
github.com/aws/aws-sdk-go Go | All versions | 1.34.0 |
Products include Amazon Aws S3 Crypto Sdk.
How do I fix CVE-2020-8912?
Upgrade github.com/aws/aws-sdk-go to 1.34.0 or later.
Is CVE-2020-8912 being exploited?
There is no known exploitation of CVE-2020-8912 in the wild and no public exploit code.
Other vulnerabilities in Google LLC AWS S3 Crypto SDK for GoLang
Sources
Also known as CLEANSTART-2026-SE38317, GHSA-7f33-f4f5-xwgw, GO-2022-0635, MINI-2243-v5cf-632h, MINI-255j-mhw4-xfqj, MINI-26xf-9557-38gc and 249 more.