Potential notify_on_release Container Escape Detected via Defend for Containers
This rule detects modification of the cgroup notify_on_release file from inside a container. When the notify_on_release flag is enabled (1) in a cgroup, then whenever the last task in the cgroup exits or attaches to…
Description
This rule detects modification of the cgroup notify_on_release file from inside a container. When the notify_on_release flag is enabled (1) in a cgroup, then whenever the last task in the cgroup exits or attaches to another cgroup, the command specified in the release_agent file is run and invoked from the host. A privileged container with SYS_ADMIN capabilities, enables a threat actor to mount a cgroup directory and modify the notify_on_release flag in order to take advantage of this feature, which could be used for further privilege escalation and container escapes to the host machine.
Detection logic
Its licence does not clear it for publishing here
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Detection requirements
- Platform
- ContainersESXiLinuxWindows
The rule states no platform. This is derived from the ATT&CK technique it maps to.
- Log source category
- event_index
MITRE ATT&CK mappings
0 exclusive techniques.This is coverage no other published rule has; it is not this rule's total technique count.
References
| Reference | Cited by |
|---|---|
| blog.trailofbits.com/2019/07/19/understanding-docker-container-escapes/ | Only this detection cites it |
| sysdig.com/blog/detecting-mitigating-cve-2022-0492-sysdig/ | 3 |
From the source
- At source
- Open at source
- Upstream identifier
- ef65e82c-d8b4-4895-9824-5f6bc6166804
- Tagged by the source as
- Data Source: Elastic Defend for ContainersDomain: ContainersNoise: UnknownOS: LinuxPerformance: FastPlatform: LinuxProfile: RecommendedResources: Investigation GuideRule Type: Event Correlation (EQL)Tactic: Privilege EscalationThreat: Container EscapeUse Case: Threat Detection
Licence
- Published under
- Elastic License 2.0Read the licence
- Attribution
- Required
Authorship
- Written by
- Published
- Sep 20, 2026
- Version
- 3