############################################################# # # COMPASS SECURITY ADVISORY # https://www.compass-security.com/research/advisories/ # ############################################################# # # Product: 3CX Phone System # Vendor: 3CX # CSNC ID: CSNC-2021-022 # CVE ID: CVE-2021-45491 # Subject: Exportable Cleartext Passwords # CWE-ID: CWE-257 (Storing Passwords in a Recoverable Format) # Severity: Medium # Effect: Credential Reuse # Author: Emanuel Duss <emanuel.duss@compass-security.com> # Date: 2022-03-17 # ############################################################# Introduction ------------ 3CX is an open-platform office phone system that runs on premise on Windows or Linux. 3CX was built for mobility, with remote work apps that offer secured communication for the whole team. With the Android, iOS and Windows apps, business communication is no longer tied to the office building. [1] During a customer project, we identified a security vulnerability in the 3CX system. The user passwords of the 3CX system are stored in plain text in the database and are also exportable in the administration interface. Affected -------- - All versions of the 3CX application are affected. - There is no fix from the vendor. Description ----------- The user passwords of the 3CX system are stored in plain text in the database and are also exportable in the administration interface. This can be verified by exporting the credentials via the admin interface or by looking into the SQL database. This issue is also already documented in the community forum since 2019 [2]. The storage of passwords in a recoverable format makes them subject to password reuse attacks by malicious users. In fact, it should be noted that recoverable encrypted passwords provide no significant benefit over plaintext passwords since they are subject not only to reuse by malicious attackers but also by malicious insiders. If a system administrator can recover a password directly, or use a brute force search on the available information, the administrator can use the password on other accounts. [3] Vulnerability Classification ---------------------------- CVSS v3.1 Metrics [4]: - CVSS Base Score: 5.5 (Medium) - CVSS Vector: AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:L/A:N Workaround / Fix ---------------- # 3CX Vendor A password hash function such as PBKDF2, bcrypt or scrypt should be used for passwords. The passwords should also be provided with a salt that is generated individually for each user. This can make attacks that use rainbow tables or pre-calculated wordlists more difficult. # 3CX Users There is no security update for this vulnerability at the moment. According to the 3CX, the vulnerability will be tackled in future redesigns of the management console. Timeline -------- 2021-12-16: Vulnerability discovered 2021-12-17: Discussed vulnerability with our customer Asked 3CX for security contact on Twitter, community forum, support email and contact form. Got response via support mail. Security contact was dpo@3cx.com Provided details Requested CVE ID @ MITRE 2021-12-25: Assigned CVE-2021-45491 2022-01-03: Asked vendor if they understood the vulnerability. Answer: Report was distributed internally. 2022-01-18: Asked vendor for any updates. 2022-02-02: Asked vendor for any updates. 2022-02-10: Asked vendor for any updates. 3CX can't tell when the issue will be fixed. 2022-03-11: Asked vendor for any updates. 3CX thanked for the report. Issues will be tackled in future redesigns of the management console. 2022-03-17: Coordinated public disclosure Acknowledgement --------------- Thanks 3CX for the coordinated disclosure. References ---------- [1] https://www.3cx.com/ [2] https://www.3cx.de/forum/threads/klartext-passwort-willkommen-mail-also-auch-in-db.94280/ [3] https://cwe.mitre.org/data/definitions/257.html [4] https://nvd.nist.gov/vuln-metrics/cvss/v3-calculator?vector=AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:L/A:N&version=3.1