CVE-2021-37624Disclosure(freeswitch / freeswitch)

LOWCVSS 7.5 · HIGH

Signal is active with 2 mentions in latest observed window

Immediate actions

  • Patch freeswitch freeswitch systems immediately

Recommended action window: Monitor and triage in normal cycle

NVD 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. 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.

0.5/ 10 priority

Sources & remediation

Weakness type (CWE)
CWE-287CWE-306

Priority

LOW

Exploitation

NONE

PoC

YES

Patch

AVAILABLE

Momentum

NONE

Are you affected?

If you run products in this scope, you should treat this CVE as relevant to your environment.

  • freeswitch

Threat summary

  • Patch or workaround signal is available
  • 2 mentions across 1 observed day

What's happening

  • Patch or workaround mentioned in 1 signal
  • Technical details provided in 2 signals
  • Disclosure: 1 classified signal
  • 2 total mentions across 1 day

Affected systems

Vendors
Products
freeswitch

Deep dive

Activity timeline2 mentions / 1d
01122Mentions · 2026-08-31: 2Patch / Workaround · 2026-08-31: 1Technical Details · 2026-08-31: 208-31
Signal classification2 categories
Disclosure
150.0%
Patch
150.0%
Full discourse2 posts
  • Sandro Gauci@sandrogauci
    Disclosure

    2/ FreeSWITCH treats a SIP MESSAGE sent to a sip:api+ URI as a command to run. On an outdated install still carrying the unauthenticated MESSAGE behaviour from CVE-2021-37624, which we reported back in 2021, the two combine into unauthenticated RCE.

    Post summary

    The text discloses that FreeSWITCH can execute commands from a SIP MESSAGE to a sip:api+ URI, and when combined with the legacy CVE-2021-37624 unauthenticated MESSAGE vulnerability, this results in an unauthenticated remote code execution on outdated installations.

    10010135
    3.9K followersView on X
  • Pierson-Tech@Pierson_Tech
    Patch

    @enablesecurity One detail worth calling out: this becomes unauthenticated RCE when api-chat is reachable on an older FreeSWITCH with the CVE-2021-37624 behavior. Upgrade to 1.11.3, then confirm nobody re-enabled enable-chat-api-proto during compatibility testing.

    Post summary

    The tweet alerts that older FreeSWITCH instances exposed to api‑chat can suffer unauthenticated RCE under CVE‑2021‑37624 conditions and recommends upgrading to version 1.11.3 (and disabling enable‑chat‑api‑proto) to mitigate the risk.

    0000056
    59 followersView on X
CPE platform detail1 entries

1 of 1 entries

PartVendorProductVersionTarget SWTarget HW
Appfreeswitchfreeswitch---

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