What’s Vulnerable › Vulnerabilities

CVE-2020-8897: Robustness weakness in AWS KMS and Encryption SDKs

• Severity: high (CVSS 8.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2020-11-16 · updated 2026-06-17
• Weakness: CWE-310

Description

A weak robustness vulnerability exists in the AWS Encryption SDKs for Java, Python, C and Javalcript prior to versions 2.0.0. Due to the non-committing property of AES-GCM (and other AEAD ciphers such as AES-GCM-SIV or (X)ChaCha20Poly1305) used by the SDKs to encrypt messages, an attacker can craft a unique cyphertext which will decrypt to multiple different results, and becomes especially relevant in a multi-recipient setting. We recommend users update their SDK to 2.0.0 or later.

Affected products

• Amazon AWS SDK: before 2.0.0 — fixed in 2.0.0

How to fix

Upgrade to a fixed version: Amazon AWS SDK 2.0.0. Check the vendor advisory for mitigations.

References

• https://aws.amazon.com/blogs/security/improved-client-side-encryption-explicit-keyids-and-key-commitment/
• https://github.com/google/security-research/security/advisories/GHSA-wqgp-vphw-hphf
• https://aws.amazon.com/blogs/security/improved-client-side-encryption-explicit-keyids-and-key-commitment/
• https://github.com/google/security-research/security/advisories/GHSA-wqgp-vphw-hphf

Get alerted when CVE-2020-8897 or the next vulnerability affects your stack