CVE-2021-37624
Published: 25 October 2021
Summary
CVE-2021-37624 is a high-severity Improper Authentication (CWE-287) vulnerability in Freeswitch Freeswitch. Its CVSS base score is 7.5 (High).
Operationally, ranked in the top 14.9% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2021-24182
Vulnerability details
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. Prior to version 1.10.7, FreeSWITCH does not authenticate SIP MESSAGE requests, leading to spam and…
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message spoofing. By default, SIP requests of the type MESSAGE (RFC 3428) are not authenticated in the affected versions of FreeSWITCH. MESSAGE requests are relayed to SIP user agents registered with the FreeSWITCH server without requiring any authentication. Although this behaviour can be changed by setting the `auth-messages` parameter to `true`, it is not the default setting. Abuse of this security issue allows attackers to send SIP MESSAGE messages to any SIP user agent that is registered with the server without requiring authentication. Additionally, since no authentication is required, chat messages can be spoofed to appear to come from trusted entities. Therefore, abuse can lead to spam and enable social engineering, phishing and similar attacks. This issue is patched in version 1.10.7. Maintainers recommend that this SIP message type is authenticated by default so that FreeSWITCH administrators do not need to be explicitly set the `auth-messages` parameter. When following such a recommendation, a new parameter can be introduced to explicitly disable authentication.
- CWE(s)
Related Threats
No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Session content review can reveal authentication bypasses or failures in session establishment.
Assessments check authentication mechanisms for correct implementation and effectiveness, reducing successful authentication bypass attempts.
Documented IA policy and procedures require proper authentication mechanisms to be defined and followed, reducing improper authentication.
Requires adaptive authentication under specific conditions, directly strengthening authentication mechanisms against improper or insufficient authentication.
Identity providers centralize and enforce authentication mechanisms, reducing improper authentication.
Requires unique identification and authentication of organizational users, directly preventing improper authentication.
Enforces unique device identification and authentication before any connection is established, directly mitigating improper authentication weaknesses.
Directly requires implementation of compliant authentication mechanisms to cryptographic modules, preventing improper authentication.