Elastic Security Detection Rules

Potential Container Escape via Kernel core_pattern Modification

Last updated 2 days ago on 2026-07-02
Created 2 days ago on 2026-07-02

About

The Linux kernel invokes the program named in "/proc/sys/kernel/core_pattern" whenever a process core-dumps. When that value begins with a pipe (|), the kernel runs the handler from the host's initial namespace as root, regardless of where the crashing process lived. Because the core-dump up-call is not namespaced, a process inside a container that can write core_pattern can register an attacker-controlled handler and then deliberately crash a process to have it execute on the host as root, resulting in a full container-to-host escape.
Tags
Domain: EndpointDomain: ContainerDomain: KubernetesOS: LinuxUse Case: Threat DetectionTactic: Privilege EscalationData Source: Elastic DefendData Source: Elastic EndgameData Source: Auditd ManagerData Source: CrowdstrikeData Source: SentinelOneData Source: Elastic Defend for ContainersLanguage: eql
Severity
medium
Risk Score
47
MITRE ATT&CK™

Privilege Escalation (TA0004)(external, opens in a new tab or window)

↳ Escape to Host (T1611)(external, opens in a new tab or window)

License
Elastic License v2(external, opens in a new tab or window)

Definition

Rule Type
Event Correlation Rule
Integration Pack
Prebuilt Security Detection Rules
Index Patterns
auditbeat-*endgame-*logs-auditd_manager.auditd-*logs-crowdstrike.fdr*logs-endpoint.events.process*logs-sentinel_one_cloud_funnel.*logs-cloud_defend.process*
Related Integrations

endpoint(external, opens in a new tab or window)

auditd_manager(external, opens in a new tab or window)

crowdstrike(external, opens in a new tab or window)

sentinel_one_cloud_funnel(external, opens in a new tab or window)

cloud_defend(external, opens in a new tab or window)

Query
text code block:
process where host.os.type == "linux" and event.type == "start" and
event.action in ("exec", "exec_event", "start", "ProcessRollup2", "executed", "process_started") and
process.args like ("*/proc/sys/kernel/core_pattern*", "*kernel.core_pattern*") and
?process.parent.executable != null and
(
  process.name in ("tee", "cp", "mv", "dd") or
  (
    process.name == "sysctl" and
    process.args like ("*-w*", "*core_pattern*")
  ) or
  (
    process.name in ("bash", "dash", "sh", "zsh", "ksh", "fish", "ash", "mksh", "busybox") and
    process.args == "-c" and process.args like ("*echo *", "*printf *")
  )
) and
not ?process.parent.executable in ("/usr/lib/systemd/systemd", "/usr/bin/kdumpctl", "/usr/sbin/abrtd", "/usr/bin/apport")

Install detection rules in Elastic Security

Detect Potential Container Escape via Kernel core_pattern Modification in the Elastic Security detection engine by installing this rule into your Elastic Stack.

To setup this rule, check out the installation guide for Prebuilt Security Detection Rules(external, opens in a new tab or window).