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Sipwise C5 NGCP CSC CSRF Click2Dial Exploit

High
Advisory ID
ZSL-2021-5649
Release Date
23 April 2021
Vendor
Affected Version
NGCP www_admin version 3.6.7
Tested On
Apache/2.2.22 (Debian), Apache/2.2.16 (Debian), nginx
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.

Proof of Concept
Disclosure Timeline
13.04.2021Vulnerability discovered.
19.04.2021Contact with the vendor.
22.04.2021No response from the vendor.
23.04.2021Public security advisory released.
26.04.2021Vendor responds with clarification of vulnerable versions and working on fixes.
26.04.2021The 'call2dial' was only available in www_csc, which has not been used for 7 years now.
Credits
Vulnerability discovered by Gjoko Krstic
References
Changelog
23.04.2021Initial release
25.04.2021Added reference [5], [6], [7], [8] and [9]
06.05.2021Changed affected version and added vendor status