PT-2020-20364 · Amazon Web Services · Aws S3 Crypto Sdk For Golang

Sophie Schmieg · Published 2020-08-11 · Updated 2024-11-20 · CVE-2020-8911

Positive Technologies (AI Summary)

CVSS v3.1

5.6

Medium

Base vector

AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N

Name of the Vulnerable Software and Affected Versions AWS S3 Crypto SDK for GoLang versions prior to V2

Description A padding oracle vulnerability exists in the AWS S3 Crypto SDK for GoLang, allowing an attacker with write access to the target's S3 bucket and the ability to observe decryption failures to reconstruct the plaintext with a significant number of queries to the endpoint. This is achieved by exploiting CBC's ability to manipulate the bytes of the next block and PKCS5 padding errors. The vulnerability poses insider risks and privilege escalation risks, potentially circumventing KMS controls for stored data.

Recommendations Update the SDK to V2 or later and re-encrypt files to mitigate the risk. For files encrypted with CBC mode in older versions, re-encrypt them with AES-GCM to resolve the issue. Using version 2 of the S3 crypto SDK will prevent the creation of new vulnerable files, but old files remain vulnerable until they are re-encrypted.

Exploit

Fix

Use of a Broken Cryptographic Algorithm

Weakness Enumeration

CWE-327

Related Identifiers

CVE-2020-8911

GHSA-F5PG-7WFW-84Q9

GO-2022-0646

OPENSUSE-SU-2024:14513-1

Affected Products

Aws S3 Crypto Sdk For Golang

References · 26

• 🔥 https://github.com/google/security-research/security/advisories/GHSA-f5pg-7wfw-84q9 · Exploit
• 🔥 https://github.com/sophieschmieg/exploits/tree/master/aws_s3_crypto_poc · Exploit
• https://aws.amazon.com/blogs/developer/updates-to-the-amazon-s3-encryption-client/?s=09 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2020-8911 · Security Note
• https://osv.dev/vulnerability/GO-2022-0646 · Vendor Advisory
• https://osv.dev/vulnerability/GHSA-f5pg-7wfw-84q9 · Vendor Advisory
• https://osv.dev/vulnerability/openSUSE-SU-2024:14513-1 · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2020-8911 · Vendor Advisory
• https://github.com/aws/aws-sdk-go/commit/ae9b9fd92af132cfd8d879809d8611825ba135f4 · Note
• https://github.com/aws/aws-sdk-go/pull/3403 · Note
• https://github.com/aws/aws-sdk-go/commit/1e84382fa1c0086362b5a4b68e068d4f8518d40e · Note
• https://github.com/aws/aws-sdk-go · Note
• https://suse.com/security/cve/CVE-2024-52308 · Note
• https://suse.com/security/cve/CVE-2024-52010 · Note
• https://suse.com/security/cve/CVE-2024-24425 · Note