huntrule

Citrix ADC/ADS Exploitation Attempts Targeting RAPI and PCIDSS Paths (CVE-2020-8193/8195)

Flags Citrix ADC/NetScaler HTTP requests whose URI queries match exploitation-related patterns for CVE-2020-8193 and CVE-2020-8195.

FreeReviewedSigma · Critical · v5
Category
webserver
Author
Florian Roth (Nextron Systems) (SigmaHQ), DRL 1.1
Published
2020-07-10
Updated
2026-07-31
AnalysisDetection
title: Citrix ADC/ADS Exploitation Attempts Targeting RAPI and PCIDSS Paths (CVE-2020-8193/8195)
id: 745bba89-ee68-412b-aecd-b4844be80ef0
status: test
description: This rule flags webserver requests whose query strings match specific Citrix ADC/ADS exploitation patterns associated with CVE-2020-8193 and CVE-2020-8195. The behavior matters because attackers may use crafted application-layer requests to trigger vulnerable code paths for unauthorized access or payload delivery. Detection relies on HTTP webserver telemetry, specifically the presence of targeted substrings within the request URI query parameters.
references:
  - https://support.citrix.com/article/CTX276688
  - https://research.nccgroup.com/2020/07/10/rift-citrix-adc-vulnerabilities-cve-2020-8193-cve-2020-8195-and-cve-2020-8196-intelligence/
  - https://dmaasland.github.io/posts/citrix.html
  - https://github.com/SigmaHQ/sigma/blob/master/rules-emerging-threats/2020/Exploits/CVE-2020-8193/web_cve_2020_8193_8195_citrix_exploit.yml
author: Florian Roth (Nextron Systems), Huntrule Team
date: 2020-07-10
modified: 2023-01-02
tags:
  - attack.initial-access
  - attack.t1190
  - cve.2020-8193
  - cve.2020-8195
  - detection.emerging-threats
logsource:
  category: webserver
detection:
  selection1:
    cs-uri-query|contains: /rapi/filedownload?filter=path:%2F
  selection2:
    cs-uri-query|contains|all:
      - /pcidss/report
      - type=all_signatures
      - sig_name=_default_signature_
  condition: 1 of selection*
falsepositives:
  - Unknown
level: critical
license: DRL-1.1
related:
  - id: 0d0d9a8a-a49e-4e27-b061-7ce4b936cfb7
    type: derived