CVE-2021-41157

Vulnerability Description

FreeSWITCH is a Software Defined Telecom Stack enabling the digital transformation from proprietary telecom switches to a software implementation that runs on any commodity hardware. By default, SIP requests of the type SUBSCRIBE are not authenticated in the affected versions of FreeSWITCH. Abuse of this security issue allows attackers to subscribe to user agent event notifications without the need to authenticate. This abuse poses privacy concerns and might lead to social engineering or similar attacks. For example, attackers may be able to monitor the status of target SIP extensions. Although this issue was fixed in version v1.10.6, installations upgraded to the fixed version of FreeSWITCH from an older version, may still be vulnerable if the configuration is not updated accordingly. Software upgrades do not update the configuration by default. SIP SUBSCRIBE messages should be authenticated by default so that FreeSWITCH administrators do not need to explicitly set the `auth-subscriptions` parameter. When following such a recommendation, a new parameter can be introduced to explicitly disable authentication.

CVSS Score

Affected Products

Related Weaknesses (CWE)

References

• http://seclists.org/fulldisclosure/2021/Oct/41Mailing ListThird Party Advisory
• https://github.com/signalwire/freeswitch/commit/b21dd4e7f3a6f1d5f7be3ea500a319a5PatchThird Party Advisory
• https://github.com/signalwire/freeswitch/releases/tag/v1.10.6Release NotesThird Party Advisory
• https://github.com/signalwire/freeswitch/security/advisories/GHSA-g7xg-7c54-rmpjExploitThird Party Advisory
• http://seclists.org/fulldisclosure/2021/Oct/41Mailing ListThird Party Advisory
• https://github.com/signalwire/freeswitch/commit/b21dd4e7f3a6f1d5f7be3ea500a319a5PatchThird Party Advisory
• https://github.com/signalwire/freeswitch/releases/tag/v1.10.6Release NotesThird Party Advisory
• https://github.com/signalwire/freeswitch/security/advisories/GHSA-g7xg-7c54-rmpjExploitThird Party Advisory