Detection rules › Sigma

CVE-2023-22518 Exploitation Attempt - Suspicious Confluence Child Process (Linux)

Status
test
Severity
high
Log source
product linux, category process_creation
Author
Andreas Braathen (mnemonic.io)
Source
github.com/SigmaHQ/sigma

Detects exploitation attempt of CVE-2023-22518 (Confluence Data Center / Confluence Server), where an attacker can exploit vulnerable endpoints to e.g. create admin accounts and execute arbitrary commands.

MITRE ATT&CK coverage

Event coverage

Rule body yaml

title: CVE-2023-22518 Exploitation Attempt - Suspicious Confluence Child Process (Linux)
id: f8987c03-4290-4c96-870f-55e75ee377f4
related:
    - id: 1ddaa9a4-eb0b-4398-a9fe-7b018f9e23db
      type: similar
status: test
description: |
    Detects exploitation attempt of CVE-2023-22518 (Confluence Data Center / Confluence Server), where an attacker can exploit vulnerable endpoints to e.g. create admin accounts and execute arbitrary commands.
references:
    - https://confluence.atlassian.com/security/cve-2023-22518-improper-authorization-vulnerability-in-confluence-data-center-and-server-1311473907.html
    - https://www.huntress.com/blog/confluence-to-cerber-exploitation-of-cve-2023-22518-for-ransomware-deployment
    - https://github.com/ForceFledgling/CVE-2023-22518
author: Andreas Braathen (mnemonic.io)
date: 2023-11-14
tags:
    - attack.execution
    - attack.t1059
    - attack.initial-access
    - attack.t1190
    - cve.2023-22518
    - detection.emerging-threats
logsource:
    category: process_creation
    product: linux
detection:
    selection_parent:
        ParentImage|endswith: '/java'
        ParentCommandLine|contains: 'confluence'
    selection_child:
        # Only children associated with known campaigns
        Image|endswith:
            - '/bash'
            - '/curl'
            - '/echo'
            - '/wget'
    filter_main_ulimit:
        CommandLine|contains: 'ulimit -u'
    condition: all of selection_* and not 1 of filter_main_*
falsepositives:
    - Unlikely
level: high

Stages and Predicates

Stage 0: condition

all of selection_* and not 1 of filter_main_*

Stage 1: selection_parent

selection_parent:
    ParentImage|endswith: '/java'
    ParentCommandLine|contains: 'confluence'

Stage 2: selection_child

selection_child:
    Image|endswith:
        - '/bash'
        - '/curl'
        - '/echo'
        - '/wget'

Stage 3: not filter_main_ulimit

filter_main_ulimit:
    CommandLine|contains: 'ulimit -u'

Exclusions

Top-level NOT(...) conjuncts: predicates this rule actively suppresses.

FieldKindExcluded values
CommandLinematchulimit -u

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
Imageends_with
  • /bash
  • /curl
  • /echo
  • /wget
ParentCommandLinematch
  • confluence
ParentImageends_with
  • /java