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Description

The following analytic detects potential exploitation of the critical Adobe ColdFusion vulnerability, CVE-2023-26360. This flaw, rooted in the deserialization of untrusted data, enables Unauthenticated Arbitrary File Read. Exploitation often targets specific ColdFusion paths, especially related to CKEditor's file manager.
Our analytic pinpoints exploitation by monitoring web requests to the "/cf_scripts/scripts/ajax/ckeditor/*" path. This focus helps differentiate malicious activity from standard ColdFusion traffic. For SOCs, detecting such attempts is vital given the vulnerability's CVSS score of 9.8, signaling its severity. Successful exploitation can lead to unauthorized data access, further attacks, or severe operational disruptions.
If a true positive arises, it indicates an active breach attempt, potentially causing data theft, operational disruption, or reputational damage. In essence, this analytic provides a targeted approach to identify attempts exploiting a high-risk ColdFusion vulnerability. While false positives may occur from legitimate accesses, any alerts should be treated as high-priority, warranting immediate investigation to ensure security.

  • Type: TTP
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Web
  • Last Updated: 2023-08-23
  • Author: Michael Haag, Splunk
  • ID: 695aceae-21db-4e7f-93ac-a52e39d02b93

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1190 Exploit Public-Facing Application Initial Access
Kill Chain Phase
  • Delivery
NIST
  • DE.CM
CIS20
  • CIS 13
CVE
ID Summary CVSS
CVE-2023-26360 Adobe ColdFusion versions 2018 Update 15 (and earlier) and 2021 Update 5 (and earlier) are affected by an Improper Access Control vulnerability that could result in arbitrary code execution in the context of the current user. Exploitation of this issue does not require user interaction. None
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| tstats count min(_time) as firstTime max(_time) as lastTime from datamodel=Web where Web.url IN ("/cf_scripts/scripts/ajax/ckeditor/*") Web.status=200 by Web.http_user_agent, Web.status Web.http_method, Web.url, Web.url_length, Web.src, Web.dest, sourcetype 
| `drop_dm_object_name("Web")` 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `adobe_coldfusion_unauthenticated_arbitrary_file_read_filter`

Macros

The SPL above uses the following Macros:

:information_source: adobe_coldfusion_unauthenticated_arbitrary_file_read_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required fields

List of fields required to use this analytic.

  • _time
  • Web.http_method
  • Web.url
  • Web.url_length
  • Web.src
  • Web.dest
  • Web.http_user_agent
  • Web.status
  • sourcetype

How To Implement

This detection requires the Web datamodel to be populated from a supported Technology Add-On like Splunk for Apache, Splunk for Nginx, or Splunk for Palo Alto.

Known False Positives

In the wild, we have observed three different types of attempts that could potentially trigger false positives if the HTTP status code is not in the query. Please check this github gist for the specific URIs : https://gist.github.com/patel-bhavin/d10830f3f375a2397233f6a4fe38d5c9 . These could be legitimate requests depending on the context of your organization. Therefore, it is recommended to modify the analytic as needed to suit your specific environment.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
45.0 90 50 Possible exploitation of CVE-2023-26360 against $dest$.

:information_source: The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

Reference

Test Dataset

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

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