Rukovoditel CRM up to 3.6/3.6.4 API Endpoint /api/tel/zadarma.php zd_echo cross site scripting

Summaryinfo

A vulnerability, which was classified as problematic, was found in Rukovoditel CRM up to 3.6/3.6.4. Impacted is an unknown function of the file /api/tel/zadarma.php of the component API Endpoint. The manipulation of the argument zd_echo results in cross site scripting. This vulnerability was named CVE-2026-31845. The attack may be performed from remote. There is no available exploit. You should upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as problematic, was found in Rukovoditel CRM up to 3.6/3.6.4. Affected is some unknown functionality of the file /api/tel/zadarma.php of the component API Endpoint. The manipulation of the argument zd_echo with an unknown input leads to a cross site scripting vulnerability. CWE is classifying the issue as CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. This is going to have an impact on integrity. CVE summarizes:

A pre-authenticated reflected cross-site scripting (XSS) vulnerability exists in Rukovoditel CRM version 3.6.4 in the Zadarma telephony API endpoint (/api/tel/zadarma.php). The application directly reflects user-supplied input from the 'zd_echo' GET parameter into the HTTP response without proper sanitization, output encoding, or content-type enforcement. The vulnerability is caused by the following code: if (isset($_GET['zd_echo'])) exit($_GET['zd_echo']); This results in arbitrary JavaScript execution in the context of the victim's browser when a crafted URL is visited. An attacker can exploit this issue by sending a malicious link such as: https://TARGET/api/tel/zadarma.php?zd_echo=alert('XSS') When a victim clicks the link, the payload executes in the application context, enabling session theft, phishing, and potential account takeover if sensitive users are targeted.

The weakness was presented by Shukrullo Raximov. The advisory is shared for download at forum.rukovoditel.net. This vulnerability is traded as CVE-2026-31845 since 03/09/2026. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. Successful exploitation requires user interaction by the victim. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1059.007.

By approaching the search of inurl:api/tel/zadarma.php it is possible to find vulnerable targets with Google Hacking.

Upgrading to version 3.7 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-21682). Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

• Customer Relationship Management System

Vendor

• Rukovoditel

Name

• CRM

Version

• 3.0
• 3.1
• 3.2
• 3.3
• 3.4
• 3.5
• 3.6
• 3.6.0
• 3.6.1
• 3.6.2
• 3.6.3
• 3.6.4

License

• open-source

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

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Once again VulDB remains the best source for vulnerability data.

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