CVE-2020-8912

Severity CVSS v4.0:

Pending analysis

Type:

CWE-327 Use of a Broken or Risky Cryptographic Algorithm

Publication date:

11/08/2020

Last modified:

17/08/2020

Description

A vulnerability in the in-band key negotiation exists in the AWS S3 Crypto SDK for GoLang versions prior to V2. An attacker with write access to the targeted bucket can change the encryption algorithm of an object in the bucket, which can then allow them to change AES-GCM to AES-CTR. Using this in combination with a decryption oracle can reveal the authentication key used by AES-GCM as decrypting the GMAC tag leaves the authentication key recoverable as an algebraic equation. It is recommended to update your SDK to V2 or later, and re-encrypt your files.

Impact

Vector 3.x

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N CVSS v3.1 Severity and Metrics:

Base Score: 2.50 LOW
Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N

Attack Vector (AV): Local
Attack Complexity (AC): High
Privileges Required (PR): Low
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): Low
Integrity (I): None
Availability (A): None

Base Score 3.x

2.50

Severity 3.x

LOW

Vector 2.0

AV:L/AC:L/Au:N/C:P/I:N/A:N CVSS v2.0 Severity and Metrics:

Base Score: 2.10 LOW
Vector: AV:L/AC:L/Au:N/C:P/I:N/A:N

Attack Vector (AV): Local
Attack Complexity (AC): Low
Authentication (Au): None
Confidentiality (C): Physical
Integrity (I): None
Availability (A): None