Buffer overflow in Dieboldnixdorf Wnbios64.sys
CVE-2025-70616
A stack buffer overflow vulnerability exists in the Wincor Nixdorf wnBios64.sys kernel driver (version 1.2.0.0) in the IOCTL handler for code 0x80102058. The vulnerability is caused by missing bounds checking on the user-controlled Options parameter before copying data into a 40-byte stack buffer (Src[40]) using memmove. An attacker with local access can exploit this vulnerability by sending a crafted IOCTL request with Options > 40, causing a stack buffer overflow that may lead to kernel code execution, local privilege escalation, or denial of service (system crash). Additionally, the same IOCTL handler can leak kernel addresses and other sensitive stack data when reading beyond the buffer boundaries.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.002 (12.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 13th percentile — 12.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000
Affected products
- Dieboldnixdorf Wnbios64.sys — versions 1.2.0.0
Weakness classification (CWE)
References
- github.com/250wuyifan/wnBios64-CVE (Exploit, Third Party Advisory)
Frequently asked questions
- What is CVE-2025-70616?
- CVE-2025-70616 is a high-severity vulnerability in Dieboldnixdorf Wnbios64.sys, classified under Stack-based Buffer Overflow. CVSS score: 7.8/10. Published 2026-03-05.
- How severe is CVE-2025-70616?
- High severity. CVSS v3 base score is 7.8 out of 10.