Title: Sipwise C5 NGCP CSC CSRF Click2Dial Exploit
Advisory ID: ZSL-2021-5649
Type: Local/Remote
Impact: Cross-Site Scripting
Risk: (4/5)
Release Date: 23.04.2021

Summary

Sipwise C5 (also known as NGCP - the Next Generation Communication Platform) is a SIP-based Open Source Class 5 VoIP soft-switch platform that allows you to provide rich telephony services. It offers a wide range of features (e.g. call forwarding, voicemail, conferencing etc.) that can be configured by end users in the self-care web interface. For operators, it offers a web-based administrative panel that allows them to configure subscribers, SIP peerings, billing profiles, and other entities. The administrative web panel also shows the real-time statistics for the whole system. For tight integration into existing infrastructures, Sipwise C5 provides a powerful REST API interface.

Description

The application interface allows users to perform certain actions via HTTP requests without performing any validity checks to verify the requests. This can be exploited to perform certain actions with administrative privileges if a logged-in user visits a malicious web site.

Vendor

Sipwise GmbH - https://www.sipwise.com

Affected Version

NGCP www_admin version 3.6.7

Tested On

Apache/2.2.22 (Debian)
Apache/2.2.16 (Debian)
nginx

Vendor Status

[13.04.2021] Vulnerability discovered.
[19.04.2021] Contact with the vendor.
[22.04.2021] No response from the vendor.
[23.04.2021] Public security advisory released.
[26.04.2021] Vendor responds with clarification of vulnerable versions and working on fixes.
[26.04.2021] The 'call2dial' was only available in www_csc, which has not been used for 7 years now.

PoC

sipwise_csrf.txt

Credits

Vulnerability discovered by Gjoko Krstic - <gjoko@zeroscience.mk>

References

[1] https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-31584
[2] https://nvd.nist.gov/vuln/detail/CVE-2021-31584
[3] https://www.exploit-db.com/exploits/49801
[4] https://packetstormsecurity.com/files/162318
[5] https://cxsecurity.com/issue/WLB-2021040135
[6] https://exchange.xforce.ibmcloud.com/vulnerabilities/200606
[7] https://www.incibe-cert.es/alerta-temprana/vulnerabilidades/cve-2021-31584
[8] https://www.tenable.com/cve/CVE-2021-31584
[9] https://cve.report/CVE-2021-31584

Changelog

[23.04.2021] - Initial release
[25.04.2021] - Added reference [5], [6], [7], [8] and [9]
[06.05.2021] - Changed affected version and added vendor status

Contact

Zero Science Lab

Web: https://www.zeroscience.mk
e-mail: lab@zeroscience.mk