PT-2019-3628 · Microsoft · Windows

Yaron Zinar · Published 2019-10-08 · Updated 2026-03-01 · CVE-2019-1166

Positive Technologies (AI Summary)

CVSS v3.1

5.9

Medium

Base vector

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

Name of the Vulnerable Software and Affected Versions Microsoft Windows (affected versions not specified)

Description The issue is related to insufficient authentication of NTLM packets in Windows, allowing a remote attacker to downgrade the security features of the NTLM MIC (Message Integrity Check) mechanism by modifying an NTLM packet flag without breaking the signature authenticity. This can be exploited by a man-in-the-middle attacker to bypass the NTLM MIC protection.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Weakness Enumeration

CWE-354

CWE-485

CWE-254

Related Identifiers

BDU:2019-03843

CVE-2019-1166

Affected Products

Windows

References · 8

• https://bdu.fstec.ru/vul/2019-03843 · Security Note
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-1166 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2019-1166 · Security Note
• https://msrc.microsoft.com/update-guide/en-US/advisory/CVE-2019-1166 · Vendor Advisory
• http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-1166 · Security Note
• https://osv.dev/vulnerability/CVE-2019-1166 · Vendor Advisory
• https://t.me/hybgl/706 · Telegram Post
• https://t.me/cybersecuritytechnologies/797 · Telegram Post