Potential Container Escape via Modified release_agent Fileedit
This rule detects modification of the CGroup release_agent file from inside a privileged container. The release_agent is a script that is executed at the termination of any process on that CGroup and is invoked from the host. A privileged container with SYS_ADMIN capabilities, enables a threat actor to mount a CGroup directory and modify the release_agent which could be used for further privilege escalation and container escapes to the host machine.
Rule type: eql
Rule indices:
- logs-cloud_defend*
Severity: medium
Risk score: 47
Runs every: 5m
Searches indices from: now-6m (Date Math format, see also Additional look-back time)
Maximum alerts per execution: 100
References:
- https://blog.aquasec.com/threat-alert-container-escape
- https://sysdig.com/blog/detecting-mitigating-cve-2022-0492-sysdig/
- https://book.hacktricks.xyz/linux-hardening/privilege-escalation/docker-security/docker-breakout-privilege-escalation#privileged-escape-abusing-existent-release_agent-cve-2022-0492-poc1
Tags:
- Data Source: Elastic Defend for Containers
- Domain: Container
- OS: Linux
- Use Case: Threat Detection
- Tactic: Privilege Escalation
Version: 1
Rule authors:
- Elastic
Rule license: Elastic License v2
Rule queryedit
file where event.module == "cloud_defend" and event.action == "open" and event.type == "change" and file.name : "release_agent"
Framework: MITRE ATT&CKTM
-
Tactic:
- Name: Privilege Escalation
- ID: TA0004
- Reference URL: https://attack.mitre.org/tactics/TA0004/
-
Technique:
- Name: Escape to Host
- ID: T1611
- Reference URL: https://attack.mitre.org/techniques/T1611/