CVE-2026-48982
MEDIUM
MEDIUM
Priority: 0.01
BB Relevance:
27/100
Published: 2026-06-18
Modified: 2026-10-26
First seen: 2026-10-29
Status: active
Attack Surface
No Interaction
Integ. Impact
CVSS Vector Breakdown
AV:
Local
AC:
High
PR:
Low
UI:
None
S:
Unchanged
C:
Low
I:
High
A:
Low
Description
pam_usb provides hardware authentication for Linux using ordinary removable media. In versions prior to 0.9.2, when updating a one-time pad file, a temporary file is created using open() without the O_EXCL flag. Without O_EXCL, the create operation is not atomic: two concurrent processes racing to update the same pad may both succeed in opening the file, with the second write silently overwriting the first. The one-time pad is the core replay-prevention mechanism of pam_usb. A successful race could result in the stored pad value diverging from what either process expected, potentially causing authentication failures or, in a precisely timed attack, creating a window for pad reuse. This issue has been fixed in version 0.9.2.