CVE-2020-8911
A padding oracle vulnerability exists in the AWS S3 Crypto SDK for GoLang versions prior to V2.
Does this matter?
Lower severity and a low EPSS score (0.35%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 3.1
- 5.6 MEDIUMCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N
- EPSS
- 0.35% probability · 28th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-327
- Affected
- amazon/aws s3 crypto sdk
- Source
- cve-coordination@google.com
References
- https://aws.amazon.com/blogs/developer/updates-to-the-amazon-s3-encryption-client/?s=09Vendor Advisory
- https://github.com/google/security-research/security/advisories/GHSA-f5pg-7wfw-84q9Exploit, Third Party Advisory
- https://aws.amazon.com/blogs/developer/updates-to-the-amazon-s3-encryption-client/?s=09Vendor Advisory
- https://github.com/google/security-research/security/advisories/GHSA-f5pg-7wfw-84q9Exploit, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.