CVE-2026-48064

pam_usb provides hardware authentication for Linux using ordinary removable media. Prior to 0.9.1, when a PAM service is configured with deny_remote=false in pam_usb (commonly done for display managers such as gdm-password or lightdm to bypass process/TTY heuristics for local sessions), the PAM_RHOST check in pusb_do_auth() is also skipped. PAM_RHOST is set by remote daemons (sshd, XDMCP servers) to identify the remote client address. Because the check is gated inside if (opts.deny_remote), a genuine remote XDMCP connection reaches the USB device authentication step instead of being rejected. This vulnerability is fixed in 0.9.1.

CVSS v3 8.1 HIGH

8.1^/10

CVSS v3 : HIGH

Vector :

Exploitability : 2.2 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/mcdope/pam_usb/issues/348
https://github.com/mcdope/pam_usb/security/advisories/GHSA-w38v-cw9r-x9p6
https://github.com/mcdope/pam_usb/issues/348

Configurations

No configuration.

History

26 Oct 2026, 11:10

Type	Values Removed	Values Added
Summary		(es) pam_usb proporciona autenticación de hardware para Linux utilizando medios extraíbles ordinarios. Antes de la versión 0.9.1, cuando un servicio PAM está configurado con deny_remote=false en pam_usb (comúnmente hecho para gestores de pantalla como gdm-password o lightdm para omitir la heurística de proceso/TTY para sesiones locales), la verificación de PAM_RHOST en pusb_do_auth() también se omite. PAM_RHOST es establecido por demonios remotos (servidores sshd, XDMCP) para identificar la dirección del cliente remoto. Debido a que la verificación está protegida dentro de if (opts.deny_remote), una conexión XDMCP remota genuina alcanza el paso de autenticación del dispositivo USB en lugar de ser rechazada. Esta vulnerabilidad está corregida en la versión 0.9.1.

Information

Published : 2026-05-27 20:16

Updated : 2026-10-26 11:10

NVD link : CVE-2026-48064

Mitre link : CVE-2026-48064

CVE.ORG link : CVE-2026-48064

JSON object : View

Products Affected

No product.

CWE

CWE-863

Incorrect Authorization

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