GCP Firewall Rule Modification

 1[metadata]
 2creation_date = "2020/09/21"
 3integration = ["gcp"]
 4maturity = "production"
 5updated_date = "2024/05/21"
 6
 7[rule]
 8author = ["Elastic"]
 9description = """
10Identifies when a firewall rule is modified in Google Cloud Platform (GCP) for Virtual Private Cloud (VPC) or App
11Engine. These firewall rules can be modified to allow or deny connections to or from virtual machine (VM) instances or
12specific applications. An adversary may modify an existing firewall rule in order to weaken their target's security
13controls and allow more permissive ingress or egress traffic flows for their benefit.
14"""
15false_positives = [
16    """
17    Firewall rules may be modified by system administrators. Verify that the firewall configuration change was expected.
18    Exceptions can be added to this rule to filter expected behavior.
19    """,
20]
21index = ["filebeat-*", "logs-gcp*"]
22language = "kuery"
23license = "Elastic License v2"
24name = "GCP Firewall Rule Modification"
25note = """## Setup
26
27The GCP Fleet integration, Filebeat module, or similarly structured data is required to be compatible with this rule."""
28references = [
29    "https://cloud.google.com/vpc/docs/firewalls",
30    "https://cloud.google.com/appengine/docs/standard/python/understanding-firewalls",
31]
32risk_score = 47
33rule_id = "2783d84f-5091-4d7d-9319-9fceda8fa71b"
34severity = "medium"
35tags = [
36    "Domain: Cloud",
37    "Data Source: GCP",
38    "Data Source: Google Cloud Platform",
39    "Use Case: Configuration Audit",
40    "Tactic: Defense Evasion",
41]
42timestamp_override = "event.ingested"
43type = "query"
44
45query = '''
46event.dataset:gcp.audit and event.action:(*.compute.firewalls.patch or google.appengine.*.Firewall.Update*Rule)
47'''
48
49
50[[rule.threat]]
51framework = "MITRE ATT&CK"
52[[rule.threat.technique]]
53id = "T1562"
54name = "Impair Defenses"
55reference = "https://attack.mitre.org/techniques/T1562/"
56
57
58[rule.threat.tactic]
59id = "TA0005"
60name = "Defense Evasion"
61reference = "https://attack.mitre.org/tactics/TA0005/"