CVE-2021-41158
FreeSWITCH vulnerable to SIP digest leak for configured gateways
Severity Score
Exploit Likelihood
Affected Versions
Public Exploits
1Exploited in Wild
-Decision
Descriptions
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, an attacker can perform a SIP digest leak attack against FreeSWITCH and receive the challenge response of a gateway configured on the FreeSWITCH server. This is done by challenging FreeSWITCH's SIP requests with the realm set to that of the gateway, thus forcing FreeSWITCH to respond with the challenge response which is based on the password of that targeted gateway. Abuse of this vulnerability allows attackers to potentially recover gateway passwords by performing a fast offline password cracking attack on the challenge response. The attacker does not require special network privileges, such as the ability to sniff the FreeSWITCH's network traffic, to exploit this issue. Instead, what is required for this attack to work is the ability to cause the victim server to send SIP request messages to the malicious party. Additionally, to exploit this issue, the attacker needs to specify the correct realm which might in some cases be considered secret. However, because many gateways are actually public, this information can easily be retrieved. The vulnerability appears to be due to the code which handles challenges in `sofia_reg.c`, `sofia_reg_handle_sip_r_challenge()` which does not check if the challenge is originating from the actual gateway. The lack of these checks allows arbitrary UACs (and gateways) to challenge any request sent by FreeSWITCH with the realm of the gateway being targeted. This issue is patched in version 10.10.7. Maintainers recommend that one should create an association between a SIP session for each gateway and its realm to make a check be put into place for this association when responding to challenges.
FreeSWITCH es una Pila de Telecomunicaciones Definida por Software que permite la transformación digital de los switches de telecomunicaciones propietarios a una implementación de software que se ejecuta en cualquier hardware básico. En versiones anteriores a 1.10.7, un atacante puede llevar a cabo un ataque de filtrado de compendio SIP contra FreeSWITCH y recibir la respuesta de desafío de una pasarela configurada en el servidor FreeSWITCH. Esto es realizado al desafiar las peticiones SIP de FreeSWITCH con el reino configurado como el de la pasarela, forzando así a FreeSWITCH a responder con la respuesta de desafío que es basada en la contraseña de esa pasarela objetivo. El abuso de esta vulnerabilidad permite a atacantes recuperar potencialmente las contraseñas de la puerta de enlace llevando a cabo un rápido ataque de descifrado de contraseñas fuera de línea en la respuesta de desafío. El atacante no requiere privilegios de red especiales, como la capacidad de husmear el tráfico de red de FreeSWITCH, para explotar este problema. En cambio, lo que es requerido para que este ataque funcione es la capacidad de causar que el servidor víctima envíe mensajes de petición SIP a la parte maliciosa. Además, para explotar este problema, el atacante necesita especificar el reino correcto, que en algunos casos podría considerarse secreto. Sin embargo, como muchas pasarelas son realmente públicas, esta información puede ser fácilmente recuperada. La vulnerabilidad parece deberse al código que maneja los retos en "sofia_reg.c", "sofia_reg_handle_sip_r_challenge()" que no comprueba si el reto se origina en la pasarela real. La falta de estas comprobaciones permite que UACs arbitrarias (y pasarelas) desafíen cualquier petición enviada por FreeSWITCH con el reino de la pasarela a la que se dirige. Este problema está parcheado en la versión 10.10.7. Los mantenedores recomiendan que se cree una asociación entre una sesión SIP para cada pasarela y su reino para hacer una comprobación de esta asociación cuando se responda a los desafíos
FreeSWITCH versions 1.10.6 and below suffer from a SIP digest leak vulnerability. An attacker can perform a SIP digest leak attack against FreeSWITCH and receive the challenge response of a gateway configured on the FreeSWITCH server. This is done by challenging FreeSWITCH's SIP requests with the realm set to that of the gateway, thus forcing FreeSWITCH to respond with the challenge response which is based on the password of that targeted gateway.
CVSS Scores
SSVC
- Decision:-
Timeline
- 2021-09-15 CVE Reserved
- 2021-10-25 CVE Published
- 2024-08-04 CVE Updated
- 2024-08-04 First Exploit
- 2024-09-17 EPSS Updated
- ---------- Exploited in Wild
- ---------- KEV Due Date
CWE
- CWE-200: Exposure of Sensitive Information to an Unauthorized Actor
- CWE-346: Origin Validation Error
CAPEC
References (3)
| URL | Tag | Source |
|---|---|---|
| https://github.com/signalwire/freeswitch/releases/tag/v1.10.7 | Release Notes |
| URL | Date | SRC |
|---|---|---|
| https://github.com/signalwire/freeswitch/security/advisories/GHSA-3v3f-99mv-qvj4 | 2024-08-04 |
| URL | Date | SRC |
|---|---|---|
| http://seclists.org/fulldisclosure/2021/Oct/40 | 2022-10-24 |
| URL | Date | SRC |
|---|
Affected Vendors, Products, and Versions
| Vendor | Product | Version | Other | Status | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Vendor | Product | Version | Other | Status | <-- --> | Vendor | Product | Version | Other | Status |
| Freeswitch Search vendor "Freeswitch" | Freeswitch Search vendor "Freeswitch" for product "Freeswitch" | < 1.10.7 Search vendor "Freeswitch" for product "Freeswitch" and version " < 1.10.7" | - |
Affected
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