This rule raises an issue when an insecure TLS protocol version (i.e. a protocol different from "TLSv1.2", "TLSv1.3", "DTLSv1.2", or "DTLSv1.3") is
used or allowed.
It is recommended to enforce TLS 1.2 as the minimum protocol version and to disallow older versions like TLS 1.0. Failure to do so could open the
door to downgrade attacks: a malicious actor who is able to intercept the connection could modify the requested protocol version and downgrade it to a
less secure version.
In most cases, using the default system configuration is not compliant. Indeed, an application might get deployed on a wide range of systems with
different configurations. While using a system’s default value might be safe on modern up-to-date systems, this might not be the case on older
systems. It is therefore recommended to explicitly set a safe configuration in every case.
Noncompliant Code Example
from OpenSSL import SSL
SSL.Context(SSL.SSLv3_METHOD) # Noncompliant
import ssl
ssl.SSLContext(ssl.PROTOCOL_SSLv3) # Noncompliant
For aws_cdk.aws_apigateway.DomainName:
from aws_cdk.aws_apigateway import DomainName, SecurityPolicy
class ExampleStack(Stack):
def __init__(self, scope: Construct, construct_id: str, **kwargs) -> None:
super().__init__(scope, construct_id, **kwargs)
DomainName(self, "example",
domain_name="example.com",
certificate=certificate,
security_policy=SecurityPolicy.TLS_1_0 # Noncompliant
)
For aws_cdk.aws_opensearchservice.CfnDomain:
from aws_cdk.aws_opensearchservice import CfnDomain, EngineVersion
class ExampleStack(Stack):
def __init__(self, scope: Construct, construct_id: str, **kwargs) -> None:
super().__init__(scope, construct_id, **kwargs)
CfnDomain(self, "example",
version=EngineVersion.OPENSEARCH_1_3
) # Noncompliant: enables TLS 1.0 which is a deprecated version of the protocol
Compliant Solution
from OpenSSL import SSL
context = SSL.Context(SSL.TLS_SERVER_METHOD)
context.set_min_proto_version(SSL.TLS1_3_VERSION)
import ssl
context = ssl.SSLContext(ssl.PROTOCOL_TLS_SERVER)
context.minimum_version = ssl.TLSVersion.TLSv1_3
For aws_cdk.aws_apigateway.DomainName:
from aws_cdk.aws_apigateway import DomainName, SecurityPolicy
class ExampleStack(Stack):
def __init__(self, scope: Construct, construct_id: str, **kwargs) -> None:
super().__init__(scope, construct_id, **kwargs)
DomainName(self, "example",
domain_name="example.com",
certificate=certificate,
security_policy=SecurityPolicy.TLS_1_2
)
For aws_cdk.aws_opensearchservice.CfnDomain:
from aws_cdk.aws_opensearchservice import CfnDomain, EngineVersion
class ExampleStack(Stack):
def __init__(self, scope: Construct, construct_id: str, **kwargs) -> None:
super().__init__(scope, construct_id, **kwargs)
CfnDomain(self, "example",
version=EngineVersion.OPENSEARCH_1_3
domain_endpoint_options=CfnDomain.DomainEndpointOptionsProperty(
tls_security_policy="Policy-Min-TLS-1-2-2019-07"
)
)
See
