KL-001-2024-007: Journyx Unauthenticated Password Reset Bruteforce

2024-8-8 07:51:20 Author: seclists.org(查看原文) 阅读量:4 收藏

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

The contents of this advisory are copyright(c) 2024
KoreLogic, Inc. and are licensed under a Creative Commons
Attribution Share-Alike 4.0 (United States) License:
http://creativecommons.org/licenses/by-sa/4.0/

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