Tuleap <= 9.6 Second-Order PHP Object Injection Vulnerability

• Software Link:

https://www.tuleap.org

• Affected Versions:

All versions from 5.0 to 9.6.

• Vulnerability Description:

The vulnerable code can be triggered through the User::getRecentElements() method defined in /src/common/user/User.class.php:

1425public function getRecentElements() {
1426    if ($recent_elements = $this->getPreference(self::PREFERENCE_RECENT_ELEMENTS)) {
1427        if ($recent_elements = unserialize($recent_elements)) {
1428            if (is_array($recent_elements)) {
1429                return $recent_elements;
1430            }
1431        }
1432        //somthing wrong happen. Delete the preference
1433        $this->delPreference(self::PREFERENCE_RECENT_ELEMENTS);
1434    }
1435    return array();
1436}

The vulnerability exists because this method is using the unserialize() PHP function with a value that can be arbitrarily manipulated by a user through the REST API interface. This can be exploited to inject arbitrary PHP objects into the application scope, and could allow authenticated attackers to execute arbitrary PHP code via specially crafted serialized objects. Successful exploitation of this vulnerability requires an user account with permissions to create or access artifacts in a tracker.

• Solution:

Update to version 9.7 or later.

• Disclosure Timeline:

[03/04/2017] – Vendor notified

[03/04/2017] – Vendor acknowledgement

[03/04/2017] – Vendor submitted artifact: https://tuleap.net/plugins/tracker/?aid=10118

[03/04/2017] – CVE number requested

[03/04/2017] – CVE number assigned

[05/04/2017] – Vulnerability fixed on the git repository: https://goo.gl/X2AT4z

[26/04/2017] – Version 9.7 released

[23/10/2017] – Publication of this advisory

• CVE Reference:

The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CVE-2017-7411 to this vulnerability.

• Credits:

Vulnerability discovered by Egidio Romano.