PaperCut NG Remote Web Access Attempt

 Original Source: [splunk source]
Name:PaperCut NG Remote Web Access Attempt
id:9fcb214a-dc42-4ce7-a650-f1d2cab16a6a
version:10
date:None
author:Michael Haag, Splunk
status:production
type:TTP
Description:The following analytic detects potential exploitation attempts on publicly accessible PaperCut NG servers. It identifies connections from public IP addresses to the server, specifically monitoring URI paths commonly used in proof-of-concept scripts for exploiting PaperCut NG vulnerabilities. This detection leverages web traffic data from the `Web` datamodel, focusing on specific URI paths and excluding internal IP ranges. This activity is significant as it may indicate an attempt to exploit known vulnerabilities in PaperCut NG, potentially leading to unauthorized access or control of the server. If confirmed malicious, attackers could gain administrative access, leading to data breaches or further network compromise.
Data_source:
  • -Suricata
search:| tstats `security_content_summariesonly`
count min(_time) as firstTime
max(_time) as lastTime

from datamodel=Web WHERE

Web.url IN (
"*/app?service=direct/1/PrinterDetails/printerOptionsTab.tab"
"*/app?service=direct/1/PrinterList/selectPrinter&sp=*",
"*/app?service=page/PrinterList",
"*/app?service=page/SetupCompleted"
)
NOT src IN (
"10.0.0.0/8",
"172.16.0.0/12",
"192.168.0.0/16",
"100.64.0.0/10",
"127.0.0.0/8",
"169.254.0.0/16",
"192.0.0.0/24",
"192.0.0.0/29",
"192.0.0.8/32",
"192.0.0.9/32",
"192.0.0.10/32",
"192.0.0.170/32",
"192.0.0.171/32",
"192.0.2.0/24",
"192.31.196.0/24",
"192.52.193.0/24",
"192.88.99.0/24",
"224.0.0.0/4",
"192.175.48.0/24",
"198.18.0.0/15",
"198.51.100.0/24",
"203.0.113.0/24",
"240.0.0.0/4",
"::1"
)
by Web.http_user_agent Web.http_method
Web.url,Web.url_length Web.src
Web.dest Web.dest_port

| `drop_dm_object_name("Web")`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `papercut_ng_remote_web_access_attempt_filter`


how_to_implement:To successfully implement this search you need to be ingesting information on Web traffic that include fields relevant for traffic into the `Web` datamodel.
known_false_positives:False positives may be present if you allow access to the PaperCut NG server from public IP addresses. Filter as needed.
References:
  -https://www.cisa.gov/news-events/alerts/2023/05/11/cisa-and-fbi-release-joint-advisory-response-active-exploitation-papercut-vulnerability
  -https://www.papercut.com/kb/Main/PO-1216-and-PO-1219
  -https://www.horizon3.ai/papercut-cve-2023-27350-deep-dive-and-indicators-of-compromise/
  -https://www.bleepingcomputer.com/news/security/hackers-actively-exploit-critical-rce-bug-in-papercut-servers/
  -https://www.huntress.com/blog/critical-vulnerabilities-in-papercut-print-management-software
drilldown_searches:
 name:'View the detection results for - "$dest$"'
 search:'%original_detection_search% | search dest = "$dest$"'
 earliest_offset:'$info_min_time$'
 latest_offset:'$info_max_time$'
 name:'View risk events for the last 7 days for - "$dest$"'
 search:'| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$") | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
 earliest_offset:'7d'
 latest_offset:'0'
analytic_story:['PaperCut MF NG Vulnerability']

asset_type:Web Server

mitre_attack_id:['T1190', 'T1133']

product:['Splunk Enterprise', 'Splunk Enterprise Security', 'Splunk Cloud']

category:web

security_domain:network

tags:

tests:
 name:'True Positive Test'
 attack_data:
  data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1190/papercut/papercutng-suricata.log
  source: not_applicable
  sourcetype: suricata
 test_type:'unit'
manual_test:None

Related Analytic Stories


PaperCut MF NG Vulnerability