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CVE-2025-39952
wifi: wilc1000: avoid buffer overflow in WID string configuration
Published 2025-10-04 (12 months ago) by the Linux kernel CNA. Subsystem drivers/net. Debian urgency: not yet assigned.
Debian does not build this code. The per-release build detail is under "Where it lives" below.
What to do, per Debian release
Debian's own status for CVE-2025-39952 in every release this site tracks, and what each one means in practice. Every status below is the one the Debian Security Team publishes for this CVE. source
| Release | Status | Version | What this means |
|---|---|---|---|
| Debian 12bookworm | vulnerable | 6.1.190-1 | No fix published anywhere yet, neither in Debian nor upstream for the series bookworm tracks. Watch the Debian tracker page for this CVE. Advisories for bookworm have historically landed a median of 23 days after publication. |
| Debian 13trixie | fixed | 6.12.57-1 | Update the kernel and reboot. Fixed in 6.12.57-1. A running kernel keeps the old code until the machine restarts. |
| Debian 14forky | fixed | 6.16.9-1 | Update the kernel and reboot. Fixed in 6.16.9-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 6.16.9-1 | Update the kernel and reboot. Fixed in 6.16.9-1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
Fix the following copy overflow warning identified by Smatch checker. drivers/net/wireless/microchip/wilc1000/wlan_cfg.c:184 wilc_wlan_parse_response_frame() error: '__memcpy()' 'cfg->s[i]->str' copy overflow (512 vs 65537) This patch introduces size check before accessing the memory buffer. The checks are base on the WID type of received data from the firmware. For WID string configuration, the size limit is determined by individual element size in 'struct wilc_cfg_str_vals' that is maintained in 'len' field of 'struct wilc_cfg_str'.
Where it lives
The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.
drivers/net/wireless/microchip/wilc1000/wlan_cfg.c
drivers/net/wireless/microchip/wilc1000/wlan_cfg.h
- What this is
- MICROCHIP WILC1000 WIFI DRIVERMAINTAINERS section matched on drivers/net/wireless/microchip/ · linux-wireless@vger.kernel.org · Supported
- Kernel module
- none to look for. The file would have gone into wilc1000, and Debian does not compile it into that module, so finding wilc1000 in lsmod would say nothing about this CVE.
Check it on the machine
grep -wE 'CONFIG_WILC1000|CONFIG_WLAN|CONFIG_WLAN_VENDOR_MICROCHIP' /boot/config-$(uname -r)Reads the booted kernel's own configuration, on the machine and nowhere else. =y is built in, =m is a module, and an is not set line means the code is not there.
Show whether Debian builds this, per release
Debian does not build this code. In 4 releases below, every kernel flavour Debian publishes has the switch off, so the vulnerable file is compiled into no kernel binary Debian ships.
- bookworm, trixie, forky, sidn
- n
- not enabled on any flavour - this release does not build the code
- Build switches
- CONFIG_WILC1000, CONFIG_WLAN, CONFIG_WLAN_VENDOR_MICROCHIP
- Reads as
- all on means the file is compiled; any one off means it is not.
From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS kbuild Makefiles Debian linux-config packages
Signals
- Published
- 2025-10-04 (12 months ago)source
- CVSS
- 8.8 high
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsource recompute it - Attack vector
- adjacent network (AV:A)source
- EPSS
- 0.23%, higher than 12.6% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- not yet assignedsource
- Subsystem
- drivers/net
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 4.2 | 6.6.108 | 6085291a1a58 |
| 4.2 | 6.12.49 | 2203ef417044 |
| 4.2 | 6.16.9 | ae50f8562306 |
| 4.2 | 6.17 | fe9e4d0c3931 |
Why the CNA scored it this way
Quoted from the kernel CNA's own scoring file, word for word. A highlighted metric carries the most severe value CVSS v3.1 defines for it, which is what pushes the score up. source
- AV:AAttack vector, adjacent network
- The overflow length and payload originate from the association-response management frame supplied over the air by the AP and relayed by the WILC firmware as a WID_ASSOC_RES_INFO config reply, so an attacker must be within WiFi radio range of the target (rogue/evil-twin AP or management-frame injection). Per kernel guidance, WiFi-frame-sourced bugs are Adjacent.
- AC:LAttack complexity, low
- The attacker fully controls the 16-bit length field and the payload of the association response and can force association attempts repeatedly, so the overflow triggers deterministically on every connect with no race or uncontrollable precondition.
- PR:NPrivileges required, none
- Association responses are unprotected frames exchanged before any WPA/802.1X credential verification, so the attacker needs no credentials on the target network and no account or privileges on the victim device.
- UI:NUser interaction, none
- A device with a saved profile auto-associates to a spoofed SSID, and an in-range attacker can inject a spoofed association response during an ordinary connection to a legitimate network, so no victim action is required.
- S:UScope, unchanged
- The corruption is confined to the kernel heap of the same system running the driver; no VM, IOMMU, or other security-authority boundary is crossed.
- C:HConfidentiality impact, high
- The unbounded copy reads far past the received packet inside the 96 KB RX buffer into assoc_rsp, which is then exposed to userspace as association-response IEs via wilc_wlan_cfg_get_val(), and the resulting heap corruption provides further arbitrary-read primitives.
- I:HIntegrity impact, high
- Up to 65537 bytes of fully attacker-controlled data are written past a ~648-byte kzalloc'd object, an out-of-bounds write that corrupts adjacent slab objects and is a standard primitive for control-flow hijack and privilege escalation.
- A:HAvailability impact, high
- A multi-kilobyte heap overflow reliably corrupts slab metadata and neighbouring allocations, producing kernel panics or oopses on the affected embedded/IoT device.