AWS Security Group Administrative Ingress

Severity: high
Compliance: CIS 4.1, 4.2
Tags: AWS, Security Control, Initial Access:Exploit Public-Facing Application
Reference: https://docs.aws.amazon.com/vpc/latest/userguide/VPC_SecurityGroups.html
Source: github.com/panther-labs/panther-analysis

This policy validates that AWS Security Groups don't allow unrestricted inbound traffic on port 3389 or 22, ports commonly used for the remote access protocols RDP and SSH respectively.

MITRE ATT&CK coverage

Tactic	Techniques
Initial Access	`T1190` Exploit Public-Facing Application

Rule body yaml

AnalysisType: policy
Filename: aws_security_group_administrative_ingress.py
PolicyID: "AWS.SecurityGroup.AdministrativeIngress"
DisplayName: "AWS Security Group Administrative Ingress"
Enabled: true
ResourceTypes:
  - AWS.EC2.SecurityGroup
Tags:
  - AWS
  - Security Control
  - Initial Access:Exploit Public-Facing Application
Reports:
  CIS:
    - 4.1
    - 4.2
  MITRE ATT&CK:
    - TA0001:T1190
Severity: High
Description: >
  This policy validates that AWS Security Groups don't allow unrestricted inbound traffic on
  port 3389 or 22, ports commonly used for the remote access protocols RDP and SSH respectively.
Runbook: >
  https://docs.runpanther.io/alert-runbooks/built-in-policies/aws-securitygroup-restricts-ingress-on-administrative-ports
Reference: https://docs.aws.amazon.com/vpc/latest/userguide/VPC_SecurityGroups.html
Tests:
  - Name: Inbound IP Permission On All IPs On Acceptable Ports
    ExpectedResult: true
    Resource:
      {
        "Description": "default VPC security group",
        "GroupId": "sg-abc123",
        "GroupName": "default",
        "IpPermissions":
          [
            {
              "FromPort": 30,
              "IpProtocol": "-1",
              "IpRanges": [{ "CidrIp": "0.0.0.0/0", "Description": null }],
              "Ipv6Ranges": null,
              "PrefixListIds": null,
              "ToPort": 45,
              "UserIdGroupPairs":
                [
                  {
                    "Description": null,
                    "GroupId": "sg-abc123",
                    "GroupName": null,
                    "PeeringStatus": null,
                    "UserId": "1122334455",
                    "VpcId": null,
                    "VpcPeeringConnectionId": null,
                  },
                ],
            },
          ],
        "IpPermissionsEgress":
          [
            {
              "FromPort": null,
              "IpProtocol": "-1",
              "IpRanges": [{ "CidrIp": "0.0.0.0/0", "Description": null }],
              "Ipv6Ranges": null,
              "PrefixListIds": null,
              "ToPort": null,
              "UserIdGroupPairs": null,
            },
          ],
        "OwnerId": "112233445566",
        "Tags": null,
        "VpcId": "vpc-123454321",
      }
  - Name: Inbound IP Permissions On All IPs On Restricted Ports
    ExpectedResult: false
    Resource:
      {
        "Description": "default VPC security group",
        "GroupId": "sg-abc123",
        "GroupName": "default",
        "IpPermissions":
          [
            {
              "FromPort": 22,
              "IpProtocol": "-1",
              "IpRanges": [{ "CidrIp": "0.0.0.0/0", "Description": null }],
              "Ipv6Ranges": null,
              "PrefixListIds": null,
              "ToPort": 22,
              "UserIdGroupPairs":
                [
                  {
                    "Description": null,
                    "GroupId": "sg-abc123",
                    "GroupName": null,
                    "PeeringStatus": null,
                    "UserId": "1122334455",
                    "VpcId": null,
                    "VpcPeeringConnectionId": null,
                  },
                ],
            },
          ],
        "IpPermissionsEgress":
          [
            {
              "FromPort": null,
              "IpProtocol": "-1",
              "IpRanges": [{ "CidrIp": "0.0.0.0/0", "Description": null }],
              "Ipv6Ranges": null,
              "PrefixListIds": null,
              "ToPort": null,
              "UserIdGroupPairs": null,
            },
          ],
        "OwnerId": "112233445566",
        "Tags": null,
        "VpcId": "vpc-123454321",
      }
  - Name: Inbound IP Permission On All IPv6 On Restricted Ports
    ExpectedResult: false
    Resource:
      {
        "Description": "default VPC security group",
        "GroupId": "sg-abc123",
        "GroupName": "default",
        "IpPermissions":
          [
            {
              "FromPort": 22,
              "IpProtocol": "-1",
              "IpRanges": null,
              "Ipv6Ranges": [{ "CidrIpv6": "::/0", "Description": null }],
              "PrefixListIds": null,
              "ToPort": 22,
              "UserIdGroupPairs":
                [
                  {
                    "Description": null,
                    "GroupId": "sg-abc123",
                    "GroupName": null,
                    "PeeringStatus": null,
                    "UserId": "1122334455",
                    "VpcId": null,
                    "VpcPeeringConnectionId": null,
                  },
                ],
            },
          ],
        "IpPermissionsEgress":
          [
            {
              "FromPort": null,
              "IpProtocol": "-1",
              "IpRanges": [{ "CidrIp": "0.0.0.0/0", "Description": null }],
              "Ipv6Ranges": null,
              "PrefixListIds": null,
              "ToPort": null,
              "UserIdGroupPairs": null,
            },
          ],
        "OwnerId": "112233445566",
        "Tags": null,
        "VpcId": "vpc-123454321",
      }
  - Name: Inbound IP Permission On Specific IP On Restricted Port
    ExpectedResult: true
    Resource:
      {
        "Description": "default VPC security group",
        "GroupId": "sg-abc123",
        "GroupName": "default",
        "IpPermissions":
          [
            {
              "FromPort": 22,
              "IpProtocol": "-1",
              "IpRanges": [{ "CidrIp": "1.1.1.1/32", "Description": null }],
              "Ipv6Ranges": null,
              "PrefixListIds": null,
              "ToPort": 22,
              "UserIdGroupPairs":
                [
                  {
                    "Description": null,
                    "GroupId": "sg-abc123",
                    "GroupName": null,
                    "PeeringStatus": null,
                    "UserId": "1122334455",
                    "VpcId": null,
                    "VpcPeeringConnectionId": null,
                  },
                ],
            },
          ],
        "IpPermissionsEgress":
          [
            {
              "FromPort": null,
              "IpProtocol": "-1",
              "IpRanges": [{ "CidrIp": "0.0.0.0/0", "Description": null }],
              "Ipv6Ranges": null,
              "PrefixListIds": null,
              "ToPort": null,
              "UserIdGroupPairs": null,
            },
          ],
        "OwnerId": "112233445566",
        "Tags": null,
        "VpcId": "vpc-123454321",
      }
  - Name: No Inbound IP Permissions
    ExpectedResult: true
    Resource:
      {
        "Description": "default VPC security group",
        "GroupId": "sg-abc123",
        "GroupName": "default",
        "IpPermissions":
          [
            {
              "FromPort": null,
              "IpProtocol": "-1",
              "IpRanges": null,
              "Ipv6Ranges": null,
              "PrefixListIds": null,
              "ToPort": null,
              "UserIdGroupPairs":
                [
                  {
                    "Description": null,
                    "GroupId": "sg-abc123",
                    "GroupName": null,
                    "PeeringStatus": null,
                    "UserId": "1122334455",
                    "VpcId": null,
                    "VpcPeeringConnectionId": null,
                  },
                ],
            },
          ],
        "IpPermissionsEgress":
          [
            {
              "FromPort": null,
              "IpProtocol": "-1",
              "IpRanges": [{ "CidrIp": "0.0.0.0/0", "Description": null }],
              "Ipv6Ranges": null,
              "PrefixListIds": null,
              "ToPort": null,
              "UserIdGroupPairs": null,
            },
          ],
        "OwnerId": "112233445566",
        "Tags": null,
        "VpcId": "vpc-123454321",
      }

Detection logic

Condition

IpPermissions not is_null

This rule also runs imperative logic the parser cannot express as a filter; the conditions above are the structured part it could extract.

Exclusions

Top-level NOT(...) conjuncts: predicates this rule actively suppresses.

Field	Kind	Excluded values
`IpPermissions`	is_null	(no value, null check)

`j` / `k`	Scroll down / up
`d` / `u`	Half-page down / up
`gg` / `G`	Top / bottom
`h` / `l`	History back / forward
`f`	Follow link (`Shift` = new tab)
`/`	Focus search
`?`	Toggle this help
`↑` / `↓`	Navigate search results
`Enter`	Open highlighted result
`Esc`	Close results / dialog

`type:`	`events` / `rules` / `providers`
`vendor:`	`sigma` / `elastic` / `splunk` / `kusto` / `chronicle` (vendor name alone also works: `sigma:`, `kql:`, `secops:`…)
`tactic:`	TA-id, slug, or name: `credential_access`, `TA0006`
`technique:`	technique or sub-technique ID: `T1003`, `T1003.001` (alias `tech:`)
`severity:`	`critical` / `high` / `medium` / `low` / `informational` (alias `sev:`)
`risk_score`	Numeric comparison on the Elastic risk score (0 to 100): `risk_score>50`, `risk_score<=20`, `risk_score=99` (alias `risk`; Elastic rules only)
`stages:`	Rules with exactly N pipeline stages
`correlation:`	`single_event` / `sequence` / `alternatives` / `alternatives_cross_log` / `all_required` / `correlated`
`with:`	Co-occurrence event-id; stacks (`with:4624 with:4769`) to require all, while a comma list in one occurrence (`with:4624,4769`) is an either-or group. Implies multi-event
`like:`	Structural neighbors of a rule slug (equivalents + subsumption stricter / broader): `like:comsvcs_lsass_memory_dump-splunk-sysmon`
`groupby:`	Entity-grouping substring match against `group_by_keys`: `groupby:user`, `groupby:host`
`uses:`	Rules whose predicate tree touches the field (any kind, any value): `uses:CommandLine`
`excludes:`	Rules with top-level `not()` clauses on the field (FP whitelists): `excludes:ParentImage`
`field:` / `value:`	Predicate search; narrows rule cards to those with a matching leaf and drives the indicator tier. Unquoted = substring, wildcards allowed (`value:mimikatz`)
`indicator:`	Shorthand for `field:F value:V`: `indicator:Image=*\powershell.exe`
`kind:`	Filter by predicate kind. Narrows rule cards to those carrying a matching predicate leaf (`vendor:elastic kind:cidr_match`) and drives the indicator tier: `contains` / `starts_with` / `ends_with` / `regex` / `cidr` / `eq` / `in` … (operator aliases `op:`/`match:`)
`has:` / `no:`	`sample`, `field`, `notes`, `refs`, `trace`, `thirdparty`, `rule`, `pattern`, `timewindow`, `threshold`, `newterms`, `sigma`/`elastic`/`splunk`/`kusto`/`chronicle`
`-op:val`	Exclude matches; works on most operators but not `type:`/`like:`/`has:`/`no:` (use `no:<flag>` to exclude a rule flag): `tactic:execution -vendor:splunk`. Standalone `-kind:`/`-field:`/`-value:` drop every rule carrying a matching predicate leaf (`type:rules -kind:is_null`)
`field:"…"` / `value:"…"`	Quoted value = anchored exact match (also allows spaces): `value:"net user"`
`a,b`	Comma = OR inside one operator (`vendor:sigma,elastic`, `severity:high,critical`); repeating a facet merges the same way. `field:`/`value:` never split (literal commas)
`vendors:` / `stage:`	Singular and plural spellings fold to the canonical operator and value: `tactics:` = `tactic:`, `type:event` = `type:events`, `correlation:sequences` = `correlation:sequence`, `has:thresholds` = `has:threshold`
`"quoted phrase"`	Exact-match a multi-word phrase (free text)