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Fencer Intel
high 7.8

CVE-2025-5555 json

Nixdorf Wincor PORT IO Driver IOCTL wnport.sys sub_11100 stack-based overflow

published last yr. modified last mo. also EUVD-2025-34989

cvss
7.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 14%
public exploits
0
none known

Summary

A vulnerability has been found in Nixdorf Wincor PORT IO Driver up to 1.0.0.1. This affects the function sub_11100 in the library wnport.sys of the component IOCTL Handler. Such manipulation leads to stack-based buffer overflow. Local access is required to approach this attack. The exploit has been disclosed to the public and may be used. Upgrading to version 3.0.0.1 is able to mitigate this issue. Upgrading the affected component is recommended. The vendor was contacted beforehand and was able to provide a patch very early.

Patch / fix

  • Nixdorf Wincor PORT IO Driver 3.0.0.1

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CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
total
Assessed
last yr.

Exploit prediction

0.24% chance of exploitation in the next 30 days, higher than 14% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • b.iakb.org https://b.iakb.org/2025/06/26/Wincor-Nixdorf-PORT-IO-Driver-Buffer-Overflow/ referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 8.5 CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P
CNA 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C
CNA 3.0 7.8 CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C
CNA 2.0 6.8 AV:L/AC:L/Au:S/C:C/I:C/A:C/E:POC/RL:OF/RC:C
CNA 4.0 7.1 CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CNA 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CNA 2.0 6.8 AV:L/AC:L/Au:S/C:C/I:C/A:C

Affected products

  • Nixdorf Wincor PORT IO Driver

Classification

Weakness
  • CWE-121 Stack-based Buffer Overflow
  • CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.