CVE-2026-44710
Received Received - Intake
Heap-based Buffer Overflow in pam_usb

Publication date: 2026-05-27

Last updated on: 2026-05-27

Assigner: GitHub, Inc.

Description
pam_usb provides hardware authentication for Linux using ordinary removable media. Prior to 0.8.7, src/device.c passed the return values of udisks_drive_get_serial(), udisks_drive_get_vendor(), and udisks_drive_get_model() directly to strcmp() without NULL checks. The GIO/UDisks API documentation states these accessors can return NULL for devices that do not expose the corresponding field. Passing NULL to strcmp() is undefined behaviour (typically a SIGSEGV). This vulnerability is fixed in 0.8.7.
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Meta Information
Published
2026-05-27
Last Modified
2026-05-27
Generated
2026-05-28
AI Q&A
2026-05-28
EPSS Evaluated
N/A
NVD
Affected Vendors & Products
Currently, no data is known.
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-476 The product dereferences a pointer that it expects to be valid but is NULL.
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?

The vulnerability exists in pam_usb versions prior to 0.8.7, where the code in src/device.c calls the strcmp() function with return values from udisks_drive_get_serial(), udisks_drive_get_vendor(), and udisks_drive_get_model() without checking if these values are NULL.

According to the GIO/UDisks API documentation, these functions can return NULL if the device does not expose the corresponding field. Passing NULL to strcmp() causes undefined behavior, which typically results in a segmentation fault (SIGSEGV).

This means that the software can crash or behave unexpectedly when handling certain removable media devices.


How can this vulnerability impact me? :

This vulnerability can cause the pam_usb authentication process to crash or terminate unexpectedly when it encounters removable media devices that do not provide certain device information fields.

Such crashes can lead to denial of service (DoS) conditions, potentially preventing legitimate users from authenticating using hardware tokens.

Since the vulnerability does not affect confidentiality or integrity, the main impact is availability disruption.


What immediate steps should I take to mitigate this vulnerability?

To mitigate this vulnerability, upgrade pam_usb to version 0.8.7 or later, where the issue has been fixed.


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