id: GO-2022-0646
modules:
    - module: github.com/aws/aws-sdk-go
      vulnerable_at: 1.33.21
      packages:
        - package: github.com/aws/aws-sdk-go/service/s3/s3crypto
          symbols:
            - NewEncryptionClient
            - NewDecryptionClient
summary: |-
    CBC padding oracle issue in AWS S3 Crypto SDK for golang in
    github.com/aws/aws-sdk-go
description: |-
    A padding oracle vulnerability exists in the AWS S3 Crypto SDK for GoLang
    versions prior to V2. The SDK allows users to encrypt files with AES-CBC without
    computing a Message Authentication Code (MAC), which then allows an attacker who
    has write access to the target's S3 bucket and can observe whether or not an
    endpoint with access to the key can decrypt a file, they can reconstruct the
    plaintext with (on average) 128*length (plaintext) queries to the endpoint, by
    exploiting CBC's ability to manipulate the bytes of the next block and PKCS5
    padding errors. It is recommended to update your SDK to V2 or later, and
    re-encrypt your files.
published: 2022-02-11T23:26:26Z
cves:
    - CVE-2020-8911
ghsas:
    - GHSA-f5pg-7wfw-84q9
credits:
    - Sophie Schmieg from the Google ISE team
references:
    - advisory: https://github.com/google/security-research/security/advisories/GHSA-f5pg-7wfw-84q9
    - fix: https://github.com/aws/aws-sdk-go/commit/1e84382fa1c0086362b5a4b68e068d4f8518d40e
    - fix: https://github.com/aws/aws-sdk-go/commit/ae9b9fd92af132cfd8d879809d8611825ba135f4
    - fix: https://github.com/aws/aws-sdk-go/pull/3403
    - web: https://aws.amazon.com/blogs/developer/updates-to-the-amazon-s3-encryption-client/?s=09
    - web: https://bugzilla.redhat.com/show_bug.cgi?id=1869800
    - web: https://github.com/sophieschmieg/exploits/tree/master/aws_s3_crypto_poc
notes:
    - https://github.com/advisories/GHSA-f5pg-7wfw-84q9 mistakenly lists this vulnerability as patched in 1.34.0.
source:
    id: GHSA-f5pg-7wfw-84q9
    created: 2024-12-12T15:34:22.739805-05:00
review_status: REVIEWED