CVE-2020-8897: Security issues in AWS KMS and AWS Encryption SDKs: in-band protocol negotiation and robustness

CVE-2020-8897 · Severity: low · CVSS 3.1 · Published 2020-11-16

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.

Technologies: com.amazonaws:aws-encryption-sdk-java (Maven), aws-encryption-sdk (PyPI). Vendors: Maven, PyPI.

Quick answers

Is CVE-2020-8897 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2020-8897 being exploited in the wild.
How severe is CVE-2020-8897?
Low severity, with a CVSS score of 3.1, published 16 November 2020.
Which products and versions are affected?
com.amazonaws:aws-encryption-sdk-java (Maven) ECOSYSTEM:introduced=0,fixed=2.0.0; aws-encryption-sdk (PyPI) ECOSYSTEM:introduced=0,fixed=2.0.0.
Is there a fix for CVE-2020-8897?
Yes. com.amazonaws:aws-encryption-sdk-java (Maven): upgrade to 2.0.0 or later; aws-encryption-sdk (PyPI): upgrade to 2.0.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
Am I affected by CVE-2020-8897?
Check whether you run com.amazonaws:aws-encryption-sdk-java (Maven) or aws-encryption-sdk (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • com.amazonaws:aws-encryption-sdk-java (Maven): upgrade to 2.0.0 or later
    # set com.amazonaws:aws-encryption-sdk-java to 2.0.0 in your pom.xml or build.gradle
  • aws-encryption-sdk (PyPI): upgrade to 2.0.0 or later
    pip install "aws-encryption-sdk>=2.0.0"

Affected products

  • com.amazonaws:aws-encryption-sdk-java (Maven) ECOSYSTEM:introduced=0,fixed=2.0.0
  • aws-encryption-sdk (PyPI) ECOSYSTEM:introduced=0,fixed=2.0.0

Identifiers

  • CVE-2020-8897
  • GHSA-wqgp-vphw-hphf
  • PYSEC-2020-261

This page as Markdown. Free to reuse under CC BY 4.0 with a link back.