KL-001-2024-007: Journyx Unauthenticated Password Reset Bruteforce
Title: Journyx Unauthenticated Password Reset Bruteforce
Advisory ID: KL-001-2024-007
Publication Date: 2024.08.07
Publication URL: https://korelogic.com/Resources/Advisories/KL-001-2024-007.txt
1. Vulnerability Details
      Affected Vendor: Journyx
      Affected Product: Journyx (jtime)
      Affected Version: 11.5.4
      Platform: GNU/Linux
      CWE Classification: CWE-321: Use of Hard-coded Cryptographic Key,
                          CWE-334: Small Space of Random Values,
                          CWE-799: Improper Control of Interaction Frequency
      CVE ID: CVE-2024-6890
2. Vulnerability Description
      Password reset tokens are generated using an insecure source
      of randomness. Attackers who know the username of the Journyx
      installation user can bruteforce the password reset and change
      the administrator password.
3. Technical Description
     From an unauthenticated perspective, a user can initiate the
     password reset flow by clicking the "Reset your password" button
     on the Journyx login screen and supplying a valid username. A
     password reset link containing a "random" token is sent to the
     email address associated with the username.
     The password reset token is generated using the current epoch
     and the user ID associated with the request. The user ID is
     a 128-bit UUID for every user *except* for the user created
     during the initial setup of the Journyx instance, i.e., the
     system administrator account. For this single user, the user
     ID defaults to the username. By targeting this user, the need
     to leak a UUID is removed entirely. If the Journyx instance was
     configured according to the official System Administration guide
(https://journyx.com/Files/Journyx_Sysadmin_and_Recovery_v11.pdf),
     the username is "journyx". Alternatively, the username can be
     leaked via stacktraces.
     When generating the token, a secret key is created by inserting
     the user ID inbetween the strings 'chuck' and 'palahniuk':
         mysessiontoken = 'chuck%spalahniuk' % me
     This key is used to XOR the string literal representation of
     the list object "[userID, time.time()]". The output of the XOR
     function is then base64 encoded:
         eStr = xor_str(istr, key)
         aStr = binascii.b2a_base64(eStr).strip()
     Since the user ID is a known value, only the output of
     "time.time()" (the epoch at the time of "encryption") is
     unknown. However, by opening a TCP connection and noting the
     epoch immediately after sending an HTTP request to initiate
     the password reset flow, a pool of tokens can be generated by
     incrementing the epoch. There is a high degree of certainty
     the valid reset token is contained within a pool larger than
     50,000 tokens.
     Depending upon network latency and other external factors,
     a successful bruteforce attack using these tokens can take
     anywhere from several minutes to over an hour.
4. Mitigation and Remediation Recommendation
      The vendor reports that this issue was remediated in Journyx
      v12.0.0, which is the first wholly cloud-hosted version of
      this product.
      For self-hosted versions of Journyx, one incremental
      improvement is to disable user-initiated password reset
      functionality in the application settings.
      1) Log into the JournyX web application as an administrator
      2) Navigate to Configuration -> System Settings -> Security Settings
      3) Ensure the checkbox labeled "Show a password reset button on login
         screen" is disabled.
      4) Click the "Save" button
      Another option would be to monkey patch the .pyc file that
      contains these hardcoded strings, ./wtdoc.pyc, by deploying a .py
      file that uses unique strings and then loads wtdoc_original.pyc
      (see KL-001-2024-008 and KL-001-2024-009 for examples).
5. Credit
      This vulnerability was discovered by Jaggar Henry of KoreLogic, Inc.
6. Disclosure Timeline
      2024.01.31 - KoreLogic notifies Journyx support of the intention to
                   report vulnerabilities discovered in the licensed,
                   on-premises version of the product.
      2024.01.31 - Journyx acknowledges receipt.
      2024.02.02 - KoreLogic requests a meeting with Journyx support to share
                   vulnerability details.
      2024.02.07 - KoreLogic reports vulnerability details to Journyx.
      2024.02.09 - Journyx responds that this vulnerability has been remediated
                   in the cloud-hosted version of the product.
      2024.02.21 - KoreLogic offers to test the cloud version to confirm
                   the fix; no response.
      2024.07.01 - KoreLogic notifies Journyx of impending public disclosure.
      2024.07.09 - Journyx confirms version number of the remediation.
      2024.08.07 - KoreLogic public disclosure.
7. Proof of Concept
     The following script automatically exploits this issue by initiating
     a password reset flow and bruteforces the value after generating a
     list of 50,000 tokens.
     [attacker@box]$ python unauth2rce.py --url http://redacted.com:8080/ --username foo --command id
     [*] Beginning Attack. Using the following timestamp: "1706708084.2051988"
     [+] New Password Generated: 2DCD5AE1F0F34B84A1E0F1FB5768219B
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