CVE Vulnerability

CVE-2020-8911

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.

2.1 /10

CVSS v2.0 :

V3 Legend

Vector :

Exploitability : 3.9 / Impact : 2.9

Attack Vector

Attack Complexity

Privileges Required

User Interaction

Confidentiality Impact PARTIAL

Integrity Impact NONE

Availability Impact NONE

Scope

5.6 /10

CVSS v3.0 : MEDIUM

V3 Legend

Vector :

Exploitability : 1.1 / Impact : 4

Attack Vector LOCAL

Attack Complexity HIGH

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact NONE

Availability Impact NONE

Scope CHANGED

References
Link Resource
https://aws.amazon.com/blogs/developer/updates-to-the-amazon-s3-encryption-client/?s=09 Vendor Advisory
https://github.com/google/security-research/security/advisories/GHSA-f5pg-7wfw-84q9 Exploit Third Party Advisory
Configurations

Configuration 1

cpe:2.3:a:amazon:aws_s3_crypto_sdk:*:*:*:*:*:golang:*:*
Information

Published : 2020-08-11 08:15

Updated : 2020-08-18 01:37

NVD link : CVE-2020-8911

Mitre link : CVE-2020-8911

Products Affected
No products.
CWE
CWE-327