{"cve":"CVE-2020-8912","nvd":{"published":"2020-08-11T20:15:13.323","modified":"2026-06-17T03:27:10.440","status":"Modified","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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N","score":2.5},"cwes":["CWE-327"],"references":["https://aws.amazon.com/blogs/developer/updates-to-the-amazon-s3-encryption-client/?s=09","https://github.com/google/security-research/security/advisories/GHSA-7f33-f4f5-xwgw","https://aws.amazon.com/blogs/developer/updates-to-the-amazon-s3-encryption-client/?s=09","https://github.com/google/security-research/security/advisories/GHSA-7f33-f4f5-xwgw"],"products":["amazon:aws_s3_crypto_sdk"],"source":"nvd","synced_at":"2026-10-19T21:09:20.498348299+00:00"},"epss":{"cve":"CVE-2020-8912","score":0.00231,"percentile":0.14039,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-7f33-f4f5-xwgw","url":"https://osv.dev/vulnerability/GHSA-7f33-f4f5-xwgw","summary":"In-band key negotiation issue in AWS S3 Crypto SDK for golang","modified":"2026-09-10T03:49:11.698758886Z","packages":[{"ecosystem":"Go","name":"github.com/aws/aws-sdk-go","purl":"pkg:golang/github.com/aws/aws-sdk-go","ranges":["<1.34.0"],"fixed":["1.34.0"]}]},{"id":"GO-2022-0635","url":"https://osv.dev/vulnerability/GO-2022-0635","summary":"In-band key negotiation issue in AWS S3 Crypto SDK for golang in github.com/aws/aws-sdk-go","modified":"2026-02-04T02:41:58.893164Z","packages":[{"ecosystem":"Go","name":"github.com/aws/aws-sdk-go","purl":"pkg:golang/github.com/aws/aws-sdk-go","ranges":["all versions"],"fixed":[]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}