CloudWatchSyntheticsFullAccess

Last Modified

Apr 1, 2026

April 1, 2026 at 12:46 PM UTC

Version

v14

Total Versions

Created

Mar 31, 2026

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Risk

Medium

The same capabilities in a scoped form, resource policy writes, reads across all data, or full access to a whole service. Read from this policy document alone: trust policies, boundaries and SCPs in your account still decide what actually succeeds. How this is assessed

Medium
Can launch resources that run as a more privileged role
Grants the actions of 1 documented escalation path, but only on named resources or under a condition. Review that scope before trusting it.
- lambda-006iam:PassRole + lambda:CreateFunction + lambda:AddPermissionscoped
  - iam:PassRole: condition iam:PassedToService, on arn:aws:iam::*:role/service-role/CloudWatchSyntheticsRole*
  - lambda:CreateFunction: on arn:aws:lambda:*:*:function:cwsyn-*
  - lambda:AddPermission: on arn:aws:lambda:*:*:function:cwsyn-*
Use with caution: Check which roles, users or policies fall inside the scope shown above. Within it the escalation works as documented, so keep privileged principals out of it.
Medium
Can take over existing resources that run as another role
Grants the actions of 2 documented escalation paths, but only on named resources or under a condition. Review that scope before trusting it.
- lambda-003lambda:UpdateFunctionCodescoped
  - lambda:UpdateFunctionCode: on arn:aws:lambda:*:*:function:cwsyn-*
- lambda-005lambda:UpdateFunctionCode + lambda:AddPermissionscoped
  - lambda:UpdateFunctionCode: on arn:aws:lambda:*:*:function:cwsyn-*
  - lambda:AddPermission: on arn:aws:lambda:*:*:function:cwsyn-*
Use with caution: Check which roles, users or policies fall inside the scope shown above. Within it the escalation works as documented, so keep privileged principals out of it.
Medium
Full synthetics access on every resource
Uses synthetics:* with Resource "*" and no condition, so every action AWS adds to that service later is granted too.
synthetics:*
Use with caution: The grant grows every time the service does. For long-lived access, prefer a policy that lists the actions you actually need.

Policy Document

View on GitHub

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239{
  "PolicyVersion": {
    "Document": {
      "Version": "2012-10-17",
      "Statement": [
        {
          "Effect": "Allow",
          "Action": [
            "synthetics:*"
          ],
          "Resource": "*"
        },
        {
          "Effect": "Allow",
          "Action": [
            "s3:CreateBucket",
            "s3:PutEncryptionConfiguration"
          ],
          "Resource": [
            "arn:aws:s3:::cw-syn-results-*"
          ]
        },
        {
          "Effect": "Allow",
          "Action": [
            "iam:ListRoles",
            "s3:ListAllMyBuckets",
            "xray:GetTraceSummaries",
            "xray:BatchGetTraces"
          ],
          "Resource": "*"
        },
        {
          "Effect": "Allow",
          "Action": [
            "apigateway:GET"
          ],
          "Resource": [
            "arn:aws:apigateway:*::/restapis",
            "arn:aws:apigateway:*::/restapis/*/stages",
            "arn:aws:apigateway:*::/restapis/*/stages/*/exports/swagger",
            "arn:aws:apigateway:*::/apis"
          ]
        },
        {
          "Effect": "Allow",
          "Action": [
            "s3:GetBucketLocation"
          ],
          "Resource": "arn:aws:s3:::*"
        },
        {
          "Effect": "Allow",
          "Action": [
            "s3:GetObject",
            "s3:ListBucket"
          ],
          "Resource": "arn:aws:s3:::cw-syn-*"
        },
        {
          "Effect": "Allow",
          "Action": [
            "s3:GetObjectVersion"
          ],
          "Resource": "arn:aws:s3:::aws-synthetics-library-*"
        },
        {
          "Effect": "Allow",
          "Action": [
            "iam:PassRole"
          ],
          "Resource": [
            "arn:aws:iam::*:role/service-role/CloudWatchSyntheticsRole*"
          ],
          "Condition": {
            "StringEquals": {
              "iam:PassedToService": [
                "lambda.amazonaws.com",
                "synthetics.amazonaws.com"
              ]
            }
          }
        },
        {
          "Effect": "Allow",
          "Action": [
            "iam:GetRole",
            "iam:ListAttachedRolePolicies"
          ],
          "Resource": [
            "arn:aws:iam::*:role/service-role/CloudWatchSyntheticsRole*"
          ]
        },
        {
          "Effect": "Allow",
          "Action": [
            "cloudwatch:GetMetricData",
            "cloudwatch:GetMetricStatistics",
            "cloudwatch:ListMetrics"
          ],
          "Resource": "*"
        },
        {
          "Effect": "Allow",
          "Action": [
            "cloudwatch:PutMetricAlarm",
            "cloudwatch:DeleteAlarms"
          ],
          "Resource": [
            "arn:aws:cloudwatch:*:*:alarm:Synthetics-*"
          ]
        },
        {
          "Effect": "Allow",
          "Action": [
            "cloudwatch:DescribeAlarms"
          ],
          "Resource": [
            "arn:aws:cloudwatch:*:*:alarm:*"
          ]
        },
        {
          "Effect": "Allow",
          "Action": [
            "logs:GetLogRecord",
            "logs:DescribeLogStreams",
            "logs:StartQuery",
            "logs:GetLogEvents",
            "logs:FilterLogEvents",
            "logs:GetLogGroupFields"
          ],
          "Resource": [
            "arn:aws:logs:*:*:log-group:/aws/lambda/cwsyn-*"
          ],
          "Condition": {
            "StringEquals": {
              "aws:ResourceAccount": "${aws:PrincipalAccount}"
            }
          }
        },
        {
          "Effect": "Allow",
          "Action": [
            "lambda:CreateFunction",
            "lambda:AddPermission",
            "lambda:PublishVersion",
            "lambda:UpdateFunctionCode",
            "lambda:UpdateFunctionConfiguration",
            "lambda:GetFunctionConfiguration",
            "lambda:GetFunction",
            "lambda:DeleteFunction",
            "lambda:ListTags",
            "lambda:TagResource",
            "lambda:UntagResource"
          ],
          "Resource": [
            "arn:aws:lambda:*:*:function:cwsyn-*"
          ]
        },
        {
          "Effect": "Allow",
          "Action": [
            "lambda:GetLayerVersion",
            "lambda:PublishLayerVersion",
            "lambda:DeleteLayerVersion"
          ],
          "Resource": [
            "arn:aws:lambda:*:*:layer:cwsyn-*",
            "arn:aws:lambda:*:*:layer:Synthetics:*",
            "arn:aws:lambda:*:*:layer:Synthetics_Selenium:*",
            "arn:aws:lambda:*:*:layer:AWS-CW-Synthetics*:*"
          ]
        },
        {
          "Effect": "Allow",
          "Action": [
            "ec2:DescribeVpcs",
            "ec2:DescribeSubnets",
            "ec2:DescribeSecurityGroups"
          ],
          "Resource": [
            "*"
          ]
        },
        {
          "Effect": "Allow",
          "Action": [
            "sns:ListTopics"
          ],
          "Resource": [
            "*"
          ]
        },
        {
          "Effect": "Allow",
          "Action": [
            "sns:CreateTopic",
            "sns:Subscribe",
            "sns:ListSubscriptionsByTopic"
          ],
          "Resource": [
            "arn:*:sns:*:*:Synthetics-*"
          ]
        },
        {
          "Effect": "Allow",
          "Action": [
            "kms:ListAliases"
          ],
          "Resource": "*"
        },
        {
          "Effect": "Allow",
          "Action": [
            "kms:DescribeKey"
          ],
          "Resource": "arn:aws:kms:*:*:key/*"
        },
        {
          "Effect": "Allow",
          "Action": [
            "kms:Decrypt"
          ],
          "Resource": "arn:aws:kms:*:*:key/*",
          "Condition": {
            "StringLike": {
              "kms:ViaService": [
                "s3.*.amazonaws.com"
              ]
            }
          }
        }
      ]
    },
    "VersionId": "v14",
    "IsDefaultVersion": true,
    "CreateDate": "2026-03-31T21:12:14+00:00"
  }
}

Version History (17 recorded)

Raw history

v14updated

1 action added

Apr 1, 2026

397fc9c

v13updated

scope changed, no action added or removed

Mar 12, 2026

544c746

CloudWatchSyntheticsFullAccess - Policy Version v13