Revive Adserver Security Advisory REVIVE-SA-2019-001

• Advisory ID: REVIVE-SA-2019-001
• CVE-IDs: CVE-2019-5433, CVE-2019-5434
• Date: 2019-04-23
• Risk Level: High
• Applications affected: Revive Adserver
• Versions affected: < 4.2.0
• Versions not affected: >= 4.2.0
• Website: https://www.revive-adserver.com/

Vulnerability 1 – Deserialization of Untrusted Data

• CVE-ID: CVE-2019-5434
• CWE-ID: CWE-502
• CVSSv3 Vector: AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
• CVSS Base Score: 10
• CVSS Impact Subscore: 6.0
• CVSS Exploitability Subscore: 3.9

Description

A Deserialization of Untrusted Data vulnerability has been discovered in the Revive Adserver’s delivery XML-RPC scripts. Such vulnerability could be used to perform various types of attacks, e.g. exploit serialize-related PHP vulnerabilities or PHP object injection.

It is possible, although unconfirmed, that the vulnerability has been used by some attackers in order to gain access to some Revive Adserver instances and deliver malware through them to third party websites.

Details

An attacker could send a specifically crafted payload to the XML-RPC invocation script and trigger the unserialize() call using the “what” parameter in the “openads.spc” RPC method of adxmlrpc.php and www/delivery/axmlrpc.php. Likewise the www/delivery/dxmlrpc.php script uses unserialize() on the first parameter of the “pluginExecute” method. 

References

• https://hackerone.com/reports/512076
• https://hackerone.com/reports/542670
• https://github.com/revive-adserver/revive-adserver/commit/dffed50
• https://github.com/revive-adserver/revive-adserver/commit/a1c3db4
• https://cwe.mitre.org/data/definitions/502.html
• https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-5434

Vulnerability 2 – Open Redirect

• Vulnerability Type: URL Redirection to Untrusted Site (‘Open Redirect’) [CWE-601]
• CVE-ID: CVE-2019-5433
• CVSS Base Score: 4.2
• CVSS v3 Vector: AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N
• CVSS Impact Subscore: 2.5
• CVSS Exploitability Subscore: 1.6

Description

An Open Redirect vulnerability was discovered and reported by HackerOne user Sammy (sumni). A remote attacker can trick logged-in user to open a specially crafted link and have them redirected to any destination.

Details

Input passed via the “return_url” GET parameter to “/www/admin/account-switch.php” script is not properly sanitised and used to redirect the user to the target page.

Reference

• https://hackerone.com/reports/390663
• https://github.com/revive-adserver/revive-adserver/commit/3db7aa0
• https://cwe.mitre.org/data/definitions/601.html
• https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-5433

Solution

We strongly advise people to upgrade to the most recent 4.2.0 version of Revive Adserver as soon as possible.

In case that is not immediately feasible, we especially recommend to delete the adxmlrpc.php, www/delivery/axmlrpc.php and www/delivery/dxmlrpc.php files.

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.