EUVD-2026-32649CVSS VectorNVD
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
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3DescriptionNVD
pam_usb provides hardware authentication for Linux using ordinary removable media. Prior to 0.9.1, src/conf.c allocates heap memory proportional to n_devices, a count derived from libxml2 XPath evaluation of the config file, without first enforcing an upper bound. On 32-bit targets (armv7l, i686 -- both listed in the project Makefile), the multiplication n_devices * sizeof(t_pusb_device) wraps around size_t, causing xmalloc() to receive a very small size. Because xmalloc() only calls abort() on NULL return, a small-but-non-NULL allocation is accepted, and subsequent array writes overflow the heap. This vulnerability is fixed in 0.9.1.
AnalysisAI
Heap buffer overflow in pam_usb prior to 0.9.1 allows a local attacker with high privileges to corrupt heap memory on 32-bit Linux platforms (armv7l, i686) by supplying a crafted configuration file with an excessive device count. The root cause is an unchecked integer multiplication in src/conf.c where n_devices * sizeof(t_pusb_device) wraps around size_t on 32-bit targets, causing xmalloc() to receive a drastically undersized allocation that is silently accepted, enabling out-of-bounds writes into heap memory. …
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