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CVE-2019-1040

MEDIUM severity · CVSS 5.3
5.3CVSS MEDIUM

Summary

A tampering vulnerability exists in Microsoft Windows when a man-in-the-middle attacker is able to successfully bypass the NTLM MIC (Message Integrity Check) protection. An attacker who successfully exploited this vulnerability could gain the ability to downgrade NTLM security features. To exploit this vulnerability, the attacker would need to tamper with the NTLM exchange. The attacker could then modify flags of the NTLM packet without invalidating the signature. The update addresses the vulnerability by hardening NTLM MIC protection on the server-side.

Impact & exploitability

Attack vectorNetwork
Attack complexityHigh
Privileges requiredNone
User interactionRequired
Confidentiality impactNone
Integrity impactHigh
Availability impactNone
Exploit probability (EPSS)48%

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N

Affected products we track (3)

Recommendation

Apply the vendor fix in your normal patch cycle. Open any affected product above for its exact safe version.

Official patch: https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-1040 ↗