Elastic Security Detection Rules

Printer User (lp) Shell Execution

Last updated 6 months ago on 2025-02-04
Created a year ago on 2024-09-27

About

This detection rule addresses multiple vulnerabilities in the CUPS printing system, including CVE-2024-47176, CVE-2024-47076, CVE-2024-47175, and CVE-2024-47177. Specifically, this rule detects shell executions from the foomatic-rip parent process through the default printer user (lp). These flaws impact components like cups-browsed, libcupsfilters, libppd, and foomatic-rip, allowing remote unauthenticated attackers to manipulate IPP URLs or inject malicious data through crafted UDP packets or network spoofing. This can result in arbitrary command execution when a print job is initiated.
Tags
Domain: EndpointOS: LinuxUse Case: Threat DetectionUse Case: VulnerabilityTactic: ExecutionData Source: Elastic DefendData Source: Elastic EndgameLanguage: eql
Severity
high
Risk Score
73
MITRE ATT&CK™

Execution (TA0002)(opens in a new tab or window)

↳ Exploitation for Client Execution (T1203)(opens in a new tab or window)

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

Definition

Rule Type
Event Correlation Rule
Integration Pack
Prebuilt Security Detection Rules
Index Patterns
endgame-*logs-endpoint.events.process*
Related Integrations

endpoint(opens in a new tab or window)

Query
process where host.os.type == "linux" and event.type == "start" and
  event.action in ("exec", "exec_event") and user.name == "lp" and
  process.parent.name in ("cupsd", "foomatic-rip", "bash", "dash", "sh", "tcsh", "csh", "zsh", "ksh", "fish") and
  process.name in ("bash", "dash", "sh", "tcsh", "csh", "zsh", "ksh", "fish") and not (
    process.command_line like (
      "*/tmp/foomatic-*", "*-sDEVICE=ps2write*", "*printf*", "/bin/sh -e -c cat", "/bin/bash -c cat",
      "/bin/bash -e -c cat"
    ) or
    process.args like "gs*"
  )

Install detection rules in Elastic Security

Detect Printer User (lp) Shell Execution 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(opens in a new tab or window).