======================================================================== Revive Adserver Security Advisory REVIVE-SA-2019-002 ------------------------------------------------------------------------ https://www.revive-adserver.com/security/revive-sa-2019-002 ------------------------------------------------------------------------ CVE-IDs: t.b.a. Date: 2019-05-21 Risk Level: High Applications affected: Revive Adserver Versions affected: < 4.2.1 Versions not affected: >= 4.2.1 Website: https://www.revive-adserver.com/ ======================================================================== ======================================================================== Vulnerability 1 - Use of Cryptographically Weak PRNG ======================================================================== Vulnerability Type: Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG) [CWE-388] CVE-ID: t.b.a. CVSS Base Score: 8.1 CVSSv3 Vector: AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H CVSS Impact Subscore: 5.9 CVSS Exploitability Subscore: 2.2 ======================================================================== Description ----------- A Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG) vulnerability has been discovered in the generation of the token used for the password recovery functionality of Revive Adserver by HackerOne user paulos_. Such vulnerability could be used to gain access to existing user accounts, if the attacker has access to the password recovery URL and knows or can guess the email address associated to the target account. Details ------- An attacker could request a password reset for a known user account and exploit the usage of the weak uniqid() function to guess what the generated password recovery token could be. If successful, they could set a new password and gain access to the account. References ---------- https://hackerone.com/reports/576504 https://github.com/revive-adserver/revive-adserver/commit/51fef40 https://cwe.mitre.org/data/definitions/338.html ======================================================================== Solution ======================================================================== We strongly advise people to upgrade to the most recent 4.2.1 version of Revive Adserver. In case that is not immediately feasible, we especially recommend to delete or block the www/admin/password-recovery.php script. ======================================================================== Contact Information ======================================================================== The security contact for Revive Adserver can be reached at: <security AT revive-adserver DOT com>. Please review https://www.revive-adserver.com/security/ before doing so. -- Matteo Beccati On behalf of the Revive Adserver Team https://www.revive-adserver.com/