Description
Cryptographic algorithm downgrade in the caching layer of Amazon AWS Encryption SDK for Python before version 3.3.1 and before version 4.0.5 might allow an authenticated local threat actor to bypass key commitment policy enforcement via a shared key cache, resulting in ciphertext that can be decrypted to multiple different plaintexts. To remediate this issue, users should upgrade to version 3.3.1, 4.0.5 or above.
CVSS breakdown
CVSS 4.0
Attack Vector
Local
Attack Complexity
High
Attack Requirements
Present
Privileges Required
Low
User Interaction
None
Confidentiality (Vulnerable System)
None
Integrity (Vulnerable System)
High
Availability (Vulnerable System)
None
Confidentiality (Subsequent System)
None
Integrity (Subsequent System)
None
Availability (Subsequent System)
None
CVSS 3.1
Attack Vector
Local
Attack Complexity
High
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
None
Affected products
- AWS / AWS Encryption SDK for Python2 – 2.5.1
- AWS / AWS Encryption SDK for Python3 – 3.3.0
- AWS / AWS Encryption SDK for Python4 – 4.0.4
References
- MISChttps://aws.amazon.com/security/security-bulletins/2026-017-aws/
- PATCHhttps://github.com/aws/aws-encryption-sdk-python/releases/tag/v4.0.5
- PATCHhttps://github.com/aws/aws-encryption-sdk-python/releases/tag/v3.3.1
- VENDOR_ADVISORYhttps://github.com/aws/aws-encryption-sdk-python/security/advisories/GHSA-v638-38fc-rhfv