PT-2026-23482 · Nixdorf Wincor · Wnbios64.Sys

Published 2026-03-05 · Updated 2026-03-10 · CVE-2025-70616

Positive Technologies (AI Summary)

CVSS v3.1

7.8

High

Base vector

AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Name of the Vulnerable Software and Affected Versions Wincor Nixdorf wnBios64.sys version 1.2.0.0

Description A stack buffer overflow exists in the wnBios64.sys kernel driver within the IOCTL handler for code 0x80102058. The issue is due to a lack of bounds checking on the user-controlled Options parameter before data is copied into a 40-byte stack buffer (Src[40]) using memmove. An attacker with local access can exploit this by sending a crafted IOCTL request with Options exceeding 40 bytes, leading to a stack buffer overflow. This could result in kernel code execution, local privilege escalation, or a denial of service (system crash). The IOCTL handler may also leak kernel addresses and sensitive stack data when reading beyond buffer boundaries.

Recommendations Update to a newer version of Wincor Nixdorf wnBios64.sys that addresses this vulnerability. At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Exploit

LPE

DoS

Stack Overflow

Weakness Enumeration

CWE-121

Related Identifiers

CVE-2025-70616

Affected Products

Wnbios64.Sys

References · 6

• 🔥 https://github.com/250wuyifan/wnBios64-CVE · Exploit
• https://osv.dev/vulnerability/CVE-2025-70616 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2025-70616 · Security Note
• https://twitter.com/CVEnew/status/2030755439009247650 · Twitter Post
• https://t.me/cveNotify/154969 · Telegram Post
• https://twitter.com/infoflowcloud/status/2030757104068227500 · Twitter Post