Journyx 11.5.4 Unauthenticated Password Reset Bruteforce

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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