CVE-2020-15133
In faye-websocket before version 0.11.0, there is a lack of certification validation in TLS handshakes. The `Faye::WebSocket::Client` class uses the `EM::Connection#start_tls` method in EventMachine to implement the TLS handshake whenever a `wss:` URL is used for the connection. This method does not implement certificate verification by default, meaning that it does not check that the server presents a valid and trusted TLS certificate for the expected hostname.
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That means that any `wss:` connection made using this library is vulnerable to a man-in-the-middle attack, since it does not confirm the identity of the server it is connected to. For further background information on this issue, please see the referenced GitHub Advisory. Upgrading `faye-websocket` to v0.11.0 is recommended.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N
- Puntuación base: 8.7
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 1.06%
- Percentil entre todas las CVEs puntuadas: 63
- Fecha de la puntuación: 6/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
Tecnologías afectadas (1)
CWE
- CWE-295
- CWE-295
Referencias
- https://blog.jcoglan.com/2020/07/31/missing-tls-verification-in-faye/
- https://github.com/faye/faye-websocket-ruby/security/advisories/GHSA-2v5c-755p-p4gv
- https://blog.jcoglan.com/2020/07/31/missing-tls-verification-in-faye/
- https://github.com/faye/faye-websocket-ruby/security/advisories/GHSA-2v5c-755p-p4gv
JSON original (NVD)
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"authentication": "NONE",
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"value": "In faye-websocket before version 0.11.0, there is a lack of certification validation in TLS handshakes. The `Faye::WebSocket::Client` class uses the `EM::Connection#start_tls` method in EventMachine to implement the TLS handshake whenever a `wss:` URL is used for the connection. This method does not implement certificate verification by default, meaning that it does not check that the server presents a valid and trusted TLS certificate for the expected hostname. That means that any `wss:` connection made using this library is vulnerable to a man-in-the-middle attack, since it does not confirm the identity of the server it is connected to. For further background information on this issue, please see the referenced GitHub Advisory. Upgrading `faye-websocket` to v0.11.0 is recommended."
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"value": "En faye-websocket versiones anteriores a 0.11.0, se presenta una falta de comprobación de certificación en los protocolos de enlaces TLS. La clase \"Faye::WebSocket::Client\" usa el método \"EM::Connection #start_tls\" en EventMachine para implementar el protocolo de enlace TLS cada vez que una URL \"wss:\" es usada para la conexión. Este método no implementa la verificación de certificados por defecto, lo que significa que no comprueba que el servidor presente un certificado TLS válido y confiable para el nombre de host esperado. Eso significa que cualquier conexión \"wss:\" realizada con esta biblioteca es vulnerable a un ataque de tipo man-in-the-middle, ya que no confirma la identidad del servidor al que está conectado. Para obtener más información de fondo sobre este tema, consulte el Aviso de GitHub referenciado. Es recomendado actualizar \"faye-websocket\" a la versión v0.11.0"
}
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"lastModified": "2026-06-17T02:56:06.977",
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