[New Rule] PE via UID INT_MAX Bug (#2971)

* [New Rule] PE via UID INT_MAX Bug

* changed file name

* Should be more decisive

* fix

* Update rules/linux/privilege_escalation_linux_uid_int_max_bug.toml

Co-authored-by: Justin Ibarra <[email protected]>

* Update rules/linux/privilege_escalation_linux_uid_int_max_bug.toml

Co-authored-by: Justin Ibarra <[email protected]>

* Update rules/linux/privilege_escalation_linux_uid_int_max_bug.toml

Co-authored-by: Justin Ibarra <[email protected]>

---------

Co-authored-by: Justin Ibarra <[email protected]>
Co-authored-by: Colson Wilhoit <[email protected]>

Author: 3 people

rules/linux/privilege_escalation_linux_uid_int_max_bug.toml

@@ -0,0 +1,47 @@
+[metadata]
+creation_date = "2023/07/27"
+integration = ["endpoint"]
+maturity = "production"
+min_stack_comments = "New fields added: required_fields, related_integrations, setup"
+min_stack_version = "8.3.0"
+updated_date = "2023/07/27"
+
+[rule]
+author = ["Elastic"]
+description = """
+This rule monitors for the execution of the systemd-run command by a user with a UID that is larger than the maximum 
+allowed UID size (INT_MAX). Some older Linux versions were affected by a bug which allows user accounts with a UID 
+greater than INT_MAX to escalate privileges by spawning a shell through systemd-run. 
+"""
+from = "now-9m"
+index = ["logs-endpoint.events.*"]
+language = "eql"
+license = "Elastic License v2"
+name = "Potential Privilege Escalation via UID INT_MAX Bug Detected"
+references = [
+    "https://twitter.com/paragonsec/status/1071152249529884674", 
+    "https://github.com/mirchr/security-research/blob/master/vulnerabilities/CVE-2018-19788.sh",
+    "https://gitlab.freedesktop.org/polkit/polkit/-/issues/74"]
+risk_score = 47
+rule_id = "d55436a8-719c-445f-92c4-c113ff2f9ba5"
+severity = "medium"
+tags = ["Domain: Endpoint", "OS: Linux", "Use Case: Threat Detection", "Tactic: Privilege Escalation"]
+timestamp_override = "event.ingested"
+type = "eql"
+query = '''
+process where host.os.type == "linux" and event.action == "exec" and event.type == "start" and 
+process.name == "systemd-run" and process.args == "-t" and process.args_count >= 3 and user.id >= "1000000000"
+'''
+
+[[rule.threat]]
+framework = "MITRE ATT&CK"
+
+[[rule.threat.technique]]
+id = "T1068"
+name = "Exploitation for Privilege Escalation"
+reference = "https://attack.mitre.org/techniques/T1068/"
+
+[rule.threat.tactic]
+id = "TA0004"
+name = "Privilege Escalation"
+reference = "https://attack.mitre.org/tactics/TA0004/"