A stack buffer overflow vulnerability exists in the Wincor Nixdorf wnBios64.sys kernel…
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA. Impact type from CWE-121 and the CVSS impact.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:dieboldnixdorf:wnbios64.sys:1.2.0.0:*:*:*:*:*:*:* | 1.2.0.0 | Vulnerable | Diebold Nixdorf |
- cpe:2.3:a:dieboldnixdorf:wnbios64.sys:1.2.0.0:*:*:*:*:*:*:* Versions 1.2.0.0 Vulnerable ·Diebold Nixdorf
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2025-70616
- 2026-10-03 Alias added: GHSA-wcpg-p923-mr58
References
Sources
- CVE-2025-70616 · CVE Program
- CVE-2025-70616 · NVD
- FIRST EPSS
- GHSA-wcpg-p923-mr58 · GitHub Advisory Database · CC BY 4.0
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