CVE-2021-37624

Freeswitch vulnerability

CVSS

7.5

EPSS

3.5%

EPSS pct

88th

Exploited

No known

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 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.

Affected vendor

Freeswitch

Affected product

Freeswitch

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Weakness type (CWE)

CWE-287 — Improper Authentication
CWE-306 — Missing Authentication for Critical Function

Published

2021-10-25

Risk analysis

Based on its CVSS vector, this vulnerability is exploitable over the network, low attack complexity, requiring no privileges, no user interaction. Successful exploitation leads to high impact to integrity.

Its EPSS score of 3.5% reflects a lower probability of exploitation activity in the wild over the next 30 days, placing it above 88% of all scored CVEs.

Check your external exposure to CVE-2021-37624

Confirm whether Freeswitch Freeswitch is running on any internet-facing host or subdomain.
Match discovered service fingerprints against the version affected by CVE-2021-37624.
Prioritise remediation if the asset is public, business-critical, or near authentication/payment flows.

How ThreatPort helps with CVE-2021-37624

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