Vulnerability in Amazon AWS S3 Crypto Sdk
CVE-2020-8912
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.
Vulnerability class: POODLE (CVE-2014-3566)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 2.5 (Low). Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N.
EPSS exploit prediction
EPSS: 0.002 (12.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 13th percentile — 12.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000
Affected products
- Amazon AWS S3 Crypto Sdk
- Google Llc AWS S3 Crypto Sdk For Golang — versions stable
Weakness classification (CWE)
Public proof-of-concept exploits
References
- aws.amazon.com/blogs/developer/updates-to-the-amazon-s3-encryption-client/ (Vendor Advisory)
- github.com/google/security-research/security/advisories/GHSA-7f33-f4f5-xwgw (Exploit, Third Party Advisory)
Frequently asked questions
- What is CVE-2020-8912?
- CVE-2020-8912 is a low-severity vulnerability in Amazon AWS S3 Crypto Sdk, classified under Use of a Broken or Risky Cryptographic Algorithm. CVSS score: 2.5/10. Published 2020-08-11.
- How severe is CVE-2020-8912?
- Low severity. CVSS v3 base score is 2.5 out of 10.
- Is CVE-2020-8912 known to be exploited?
- 9 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.