diff --git a/prowler/providers/aws/services/awslambda/awslambda_service.py b/prowler/providers/aws/services/awslambda/awslambda_service.py
index 52c7cb50d3..f9c74dddc6 100644
--- a/prowler/providers/aws/services/awslambda/awslambda_service.py
+++ b/prowler/providers/aws/services/awslambda/awslambda_service.py
@@ -46,7 +46,9 @@ class Lambda:
                 for function in page["Functions"]:
                     lambda_name = function["FunctionName"]
                     lambda_arn = function["FunctionArn"]
-                    lambda_runtime = function["Runtime"]
+                    lambda_runtime = None
+                    if "Runtime" in function:
+                        lambda_runtime = function["Runtime"]
                     self.functions[lambda_name] = Function(
                         name=lambda_name,
                         arn=lambda_arn,
diff --git a/prowler/providers/aws/services/cloudwatch/cloudwatch_service.py b/prowler/providers/aws/services/cloudwatch/cloudwatch_service.py
index e6b4f28cf6..6b9df1c6be 100644
--- a/prowler/providers/aws/services/cloudwatch/cloudwatch_service.py
+++ b/prowler/providers/aws/services/cloudwatch/cloudwatch_service.py
@@ -38,11 +38,14 @@ class CloudWatch:
             describe_alarms_paginator = regional_client.get_paginator("describe_alarms")
             for page in describe_alarms_paginator.paginate():
                 for alarm in page["MetricAlarms"]:
+                    metric_name = None
+                    if "MetricName" in alarm:
+                        metric_name = alarm["MetricName"]
                     self.metric_alarms.append(
                         MetricAlarm(
                             alarm["AlarmArn"],
                             alarm["AlarmName"],
-                            alarm["MetricName"],
+                            metric_name,
                             alarm["Namespace"],
                             regional_client.region,
                         )
diff --git a/prowler/providers/aws/services/ec2/ec2_service.py b/prowler/providers/aws/services/ec2/ec2_service.py
index 5b66bcac4c..383a56cd4d 100644
--- a/prowler/providers/aws/services/ec2/ec2_service.py
+++ b/prowler/providers/aws/services/ec2/ec2_service.py
@@ -67,29 +67,46 @@ class EC2:
                             "PublicDnsName" in instance
                             and "PublicIpAddress" in instance
                         ):
-                            public_dns = instance["PublicDnsName"]
-                            public_ip = instance["PublicIpAddress"]
-                        if "IamInstanceProfile" in instance:
-                            instance_profile = instance["IamInstanceProfile"]
+                            http_tokens = None
+                            http_endpoint = None
+                            public_dns = None
+                            public_ip = None
+                            private_ip = None
+                            instance_profile = None
+                            if "MetadataOptions" in instance:
+                                http_tokens = instance["MetadataOptions"]["HttpTokens"]
+                                http_endpoint = instance["MetadataOptions"][
+                                    "HttpEndpoint"
+                                ]
+                            if (
+                                "PublicDnsName" in instance
+                                and "PublicIpAddress" in instance
+                            ):
+                                public_dns = instance["PublicDnsName"]
+                                public_ip = instance["PublicIpAddress"]
+                            if "PrivateIpAddress" in instance:
+                                private_ip = instance["PrivateIpAddress"]
+                            if "IamInstanceProfile" in instance:
+                                instance_profile = instance["IamInstanceProfile"]
 
-                        self.instances.append(
-                            Instance(
-                                instance["InstanceId"],
-                                arn,
-                                instance["State"]["Name"],
-                                regional_client.region,
-                                instance["InstanceType"],
-                                instance["ImageId"],
-                                instance["LaunchTime"],
-                                instance["PrivateDnsName"],
-                                instance["PrivateIpAddress"],
-                                public_dns,
-                                public_ip,
-                                http_tokens,
-                                http_endpoint,
-                                instance_profile,
+                            self.instances.append(
+                                Instance(
+                                    instance["InstanceId"],
+                                    arn,
+                                    instance["State"]["Name"],
+                                    regional_client.region,
+                                    instance["InstanceType"],
+                                    instance["ImageId"],
+                                    instance["LaunchTime"],
+                                    instance["PrivateDnsName"],
+                                    private_ip,
+                                    public_dns,
+                                    public_ip,
+                                    http_tokens,
+                                    http_endpoint,
+                                    instance_profile,
+                                )
                             )
-                        )
         except Exception as error:
             logger.error(
                 f"{regional_client.region} -- {error.__class__.__name__}[{error.__traceback__.tb_lineno}]: {error}"
diff --git a/prowler/providers/aws/services/emr/emr_service.py b/prowler/providers/aws/services/emr/emr_service.py
index 6826a04f27..f1795caec9 100644
--- a/prowler/providers/aws/services/emr/emr_service.py
+++ b/prowler/providers/aws/services/emr/emr_service.py
@@ -72,9 +72,14 @@ class EMR:
                     master_node_security_group = cluster_info["Cluster"][
                         "Ec2InstanceAttributes"
                     ]["EmrManagedMasterSecurityGroup"]
-                    master_node_additional_security_groups = cluster_info["Cluster"][
-                        "Ec2InstanceAttributes"
-                    ]["AdditionalMasterSecurityGroups"]
+                    master_node_additional_security_groups = None
+                    if (
+                        "AdditionalMasterSecurityGroups"
+                        in cluster_info["Cluster"]["Ec2InstanceAttributes"]
+                    ):
+                        master_node_additional_security_groups = cluster_info[
+                            "Cluster"
+                        ]["Ec2InstanceAttributes"]["AdditionalMasterSecurityGroups"]
                     self.clusters[cluster.id].master = Node(
                         security_group_id=master_node_security_group,
                         additional_security_groups_id=master_node_additional_security_groups,
diff --git a/prowler/providers/aws/services/s3/s3_service.py b/prowler/providers/aws/services/s3/s3_service.py
index d68421199a..fbd6278ead 100644
--- a/prowler/providers/aws/services/s3/s3_service.py
+++ b/prowler/providers/aws/services/s3/s3_service.py
@@ -38,8 +38,8 @@ class S3:
 
     def __list_buckets__(self, audit_info):
         logger.info("S3 - Listing buckets...")
+        buckets = []
         try:
-            buckets = []
             list_buckets = self.client.list_buckets()
             for bucket in list_buckets["Buckets"]:
                 try:
@@ -60,11 +60,11 @@ class S3:
                     logger.error(
                         f"{bucket_region} -- {error.__class__.__name__}[{error.__traceback__.tb_lineno}]: {error}"
                     )
-            return buckets
         except Exception as error:
             logger.error(
                 f"{error.__class__.__name__}[{error.__traceback__.tb_lineno}]: {error}"
             )
+        return buckets
 
     def __get_bucket_versioning__(self, bucket):
         logger.info("S3 - Get buckets versioning...")