CVE-2025-38566

Estado: ModificadaAlta (7.5)—

In the Linux kernel, the following vulnerability has been resolved:

sunrpc: fix handling of server side tls alerts

Scott Mayhew discovered a security exploit in NFS over TLS in tls_alert_recv() due to its assumption it can read data from the msg iterator's kvec..

kTLS implementation splits TLS non-data record payload between the control message buffer (which includes the type such as TLS aler or TLS cipher change) and the rest of the payload (say TLS alert's level/description) which goes into the msg payload buffer.

This patch proposes to rework how control messages are setup and used by sock_recvmsg().

Leer descripción completaMostrar menos

If no control message structure is setup, kTLS layer will read and process TLS data record types. As soon as it encounters a TLS control message, it would return an error. At that point, NFS can setup a kvec backed msg buffer and read in the control message such as a TLS alert. Msg iterator can advance the kvec pointer as a part of the copy process thus we need to revert the iterator before calling into the tls_alert_recv.

CVSS

Versión: 3.1
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Puntuación base: 7.5

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.59%
Percentil entre todas las CVEs puntuadas: 46
Fecha de la puntuación: 5/10/2026

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).

🎯 Técnicas ATT&CK

Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.

ExplotaciónT1190 Exploit Public-Facing Applicationinitial access60 %
Impacto principalT1499 Endpoint Denial of Serviceimpact55 %

Inferido por reglas deterministas a partir del vector CVSS y la CWE. Solo orientativo.

🛡️ Mitigaciones ATT&CK que cubren estas técnicas

Filter Network Traffic Vulnerability Scanning Privileged Account Management Network Segmentation Limit Access to Resource Over Network Application Isolation and Sandboxing

Tecnologías afectadas (1)

Linux — Linux Kernel

CWE

CWE-754

Referencias

JSON original (NVD)

Mostrar

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      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsunrpc: fix handling of server side tls alerts\n\nScott Mayhew discovered a security exploit in NFS over TLS in\ntls_alert_recv() due to its assumption it can read data from\nthe msg iterator's kvec..\n\nkTLS implementation splits TLS non-data record payload between\nthe control message buffer (which includes the type such as TLS\naler or TLS cipher change) and the rest of the payload (say TLS\nalert's level/description) which goes into the msg payload buffer.\n\nThis patch proposes to rework how control messages are setup and\nused by sock_recvmsg().\n\nIf no control message structure is setup, kTLS layer will read and\nprocess TLS data record types. As soon as it encounters a TLS control\nmessage, it would return an error. At that point, NFS can setup a\nkvec backed msg buffer and read in the control message such as a\nTLS alert. Msg iterator can advance the kvec pointer as a part of\nthe copy process thus we need to revert the iterator before calling\ninto the tls_alert_recv."
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      "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: sunrpc: corrección del manejo de las alertas tls del lado del servidor Scott Mayhew descubrió un exploit de seguridad en NFS sobre TLS en tls_alert_recv() debido a su suposición de que puede leer datos del kvec del iterador msg. La implementación de kTLS divide el payload del registro no de datos de TLS entre el búfer de mensajes de control (que incluye el tipo como la alerta TLS o el cambio de cifrado TLS) y el resto del payload (por ejemplo, el nivel/descripción de la alerta TLS) que va al búfer de payload msg. Este parche propone volver a trabajar cómo se configuran y utilizan los mensajes de control por sock_recvmsg(). Si no se configura ninguna estructura de mensaje de control, la capa kTLS leerá y procesará los tipos de registros de datos TLS. Tan pronto como encuentre un mensaje de control TLS, devolverá un error. En ese punto, NFS puede configurar un búfer de mensajes respaldado por kvec y leer el mensaje de control como una alerta TLS. El iterador Msg puede avanzar el puntero kvec como parte del proceso de copia, por lo tanto, debemos revertir el iterador antes de llamar a tls_alert_recv."
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