CVE-2021-1699

MEDIUM

Windows - Information Disclosure in modem.sys

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2021-1699. PoCs published by waleedassar.

AI-analyzed exploit summary This repository contains a functional proof-of-concept exploit for CVE-2021-1699, an information disclosure vulnerability in Windows modem.sys. The code demonstrates how to enumerate modem devices and leak symbolic link information via ZwQuerySymbolicLinkObject.

Description

Windows (modem.sys) Information Disclosure Vulnerability

Exploits (1)

nomisec WORKING POC 17 stars
by waleedassar · poc
https://github.com/waleedassar/CVE-2021-1699

This repository contains a functional proof-of-concept exploit for CVE-2021-1699, an information disclosure vulnerability in Windows modem.sys. The code demonstrates how to enumerate modem devices and leak symbolic link information via ZwQuerySymbolicLinkObject.

Classification
Working Poc 95%
Attack Type
Info Leak
Complexity
Moderate
Reliability
Reliable
Target: Microsoft Windows (modem.sys)
No auth needed
Prerequisites: Access to a vulnerable Windows system with a modem device
devstral-2 · analyzed Feb 18, 2026 Full analysis →

Scores

CVSS v3 5.5
EPSS 0.0210
EPSS Percentile 79.4%
Attack Vector LOCAL
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Details

Status published
Products (19)
microsoft/windows_10
microsoft/windows_10 20h2
microsoft/windows_10 1607
microsoft/windows_10 1803
microsoft/windows_10 1809
microsoft/windows_10 1909
microsoft/windows_10 2004
microsoft/windows_7
microsoft/windows_8.1
microsoft/windows_rt_8.1
... and 9 more
Published Jan 12, 2021
Tracked Since Feb 18, 2026