CVE-2019-1040
published 2019-06-12CVE-2019-1040: 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)…
PriorityP180medium5.3CVSS 3.1
AVNACHPRNUIRSUCNIHAN
ITWEXPLOITVulnCheck KEVInitial access
Exploited in the wild
EPSS
48.04%
98.7th percentile
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.
Affected
48 ranges· showing 25
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| microsoft | windows_10 | — | — |
| microsoft | windows_10 | — | — |
| microsoft | windows_10 | — | — |
| microsoft | windows_10 | — | — |
| microsoft | windows_10 | — | — |
| microsoft | windows_10 | — | — |
| microsoft | windows_10_version_1507 | >= 10.0.10240.0 < publication | publication |
| microsoft | windows_10_version_1607 | >= 10.0.14393.0 < publication | publication |
| microsoft | windows_10_version_1703 | >= 10.0.0 < publication | publication |
| microsoft | windows_10_version_1709 | >= 10.0.0 < publication | publication |
| microsoft | windows_10_version_1709_for_32-bit_systems | >= 10.0.0 < publication | publication |
| microsoft | windows_10_version_1803 | >= 10.0.0 < publication | publication |
| microsoft | windows_10_version_1809 | >= 10.0.0 < publication | publication |
| microsoft | windows_10_version_1809 | >= 10.0.17763.0 < publication | publication |
| microsoft | windows_10_version_1903_for_32-bit_systems | >= 10.0.0 < publication | publication |
| microsoft | windows_10_version_1903_for_arm64-based_systems | >= 10.0.0 < publication | publication |
| microsoft | windows_10_version_1903_for_x64-based_systems | >= 10.0.0 < publication | publication |
| microsoft | windows_7 | >= 6.1.0 < publication | publication |
| microsoft | windows_7_service_pack_1 | >= 6.1.0 < publication | publication |
| microsoft | windows_8.1 | >= 6.3.0 < publication | publication |
| microsoft | windows_server_2008 | — | — |
| microsoft | windows_server_2008_r2_service_pack_1 | >= 6.1.7601.0 < publication | publication |
| microsoft | windows_server_2008_r2_systems_service_pack_1 | >= 6.1.0 < publication | publication |
| microsoft | windows_server_2008_service_pack_2 | >= 6.0.0 < publication | publication |
| microsoft | windows_server_2008_service_pack_2 | >= 6.0.6003.0 < publication | publication |
Detection & IOCsextracted from sources · hover to see the quote
commandUnset the signing flags in the NTLM_NEGOTIATE message (NTLMSSP_NEGOTIATE_ALWAYS_SIGN, NTLMSSP_NEGOTIATE_SIGN)↗
commandUnset the following flags in the NTLM_AUTHENTICATE message: NTLMSSP_NEGOTIATE_ALWAYS_SIGN, NTLMSSP_NEGOTIATE_SIGN, NEGOTIATE_KEY_EXCHANGE, NEGOTIATE_VERSION↗
- →Detect NTLM AUTHENTICATE messages missing the MIC field — a core indicator of CVE-2019-1040 exploitation in transit. ↗
- →Monitor for unusual volume of NTLM authentication attempts from unexpected internal sources, which may indicate relay activity. ↗
- →Correlate Windows Security Event ID 4624 (successful logon) with network traffic to identify anomalous logons to Exchange or ADFS from unexpected workstations. ↗
- →Configure IDS signatures to flag NTLM authentication packets missing the MIC field. ↗
- →Watch for LLMNR or NBNS poisoning activity as a precursor to NTLM relay attacks exploiting CVE-2019-1040. ↗
- ·The exploit requires removing the version field alongside the MIC field from NTLM_AUTHENTICATE; omitting only the MIC causes an error, which can serve as a detection differentiator. ↗
- ·The attack targets HTTP servers supporting Windows Integrated Authentication (WIA) such as Exchange or ADFS; these services should be prioritised for monitoring and patching. ↗
- ·The server fails to reject NTLM_AUTHENTICATE messages missing the MIC under specific conditions — detection logic must account for this server-side acceptance behaviour. ↗
CVSS provenance
nvdv3.15.3MEDIUMCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N
nvdv3.05.9MEDIUMCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
nvdv2.04.3MEDIUMAV:N/AC:M/Au:N/C:N/I:P/A:N
vulncheck5.3MEDIUM
vendor_msrc5.3MEDIUM
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Microsoft
Windows NTLM Tampering Vulnerability
vendor_msrc·2019-06-11·CVSS 5.3
CVE-2019-1040 [MEDIUM] Windows NTLM Tampering Vulnerability
Windows NTLM Tampering Vulnerability
Description: 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.
Windows Authentication Methods: Windows Authentication Methods
Microsoft: Microsoft
Customer Action Required: Yes
Impact: Tampering
Exploit Status: Publicly Disclosed:No;Exploited:No;
GHSA
GHSA-8vpr-83m7-3f7q: A tampering vulnerability exists in Microsoft Windows when a man-in-the-middle attacker is able to successfully bypass the NTLM MIC (Message Integrity
ghsa_unreviewed·2022-05-24
CVE-2019-1040 [MEDIUM] GHSA-8vpr-83m7-3f7q: A tampering vulnerability exists in Microsoft Windows when a man-in-the-middle attacker is able to successfully bypass the NTLM MIC (Message Integrity
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, aka 'Windows NTLM Tampering Vulnerability'.
VulnCheck
Windows NTLM Tampering
vulncheck·2019·CVSS 5.3
CVE-2019-1040 [MEDIUM] Windows NTLM Tampering
Windows NTLM Tampering
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.
Affected: Microsoft Windows
Required Action: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.
Exploitation References: htt
No detection rules found.
No public exploits indexed.
Trendmicro
Manage Zero Day Exploits (ZDI) with Trend Micro Solutions
blogs_trendmicro·2021-04-28
Manage Zero Day Exploits (ZDI) with Trend Micro Solutions
Cyberbedrohungen
## How Trend Micro Helps Manage Exploited Vulnerabilities
As technological innovations evolve, protecting companies from cyber threats tomorrow secures their businesses today. Read how Trend Micro protects customers from vulnerability exploits by blocking them as early as possible.
By: Jon Clay Apr 28, 2021 Read time: ( words)
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As technological innovations evolve, protecting companies from cyber threats tomorrow secures their businesses today. Exploiting known vulnerabilities to successfully compromise an organization has long been a common tactic used by malicious actors. Whether Heartbleed, EternalBlue, or most recently Zerologon, threat actors take advantage of newly disclosed vulnerabilities in their attacks. But even with thousands of new vulnerabili
Trendmicro
Manage Zero Day Exploits (ZDI) with Trend Micro Solutions
blogs_trendmicro·2021-04-28
Manage Zero Day Exploits (ZDI) with Trend Micro Solutions
Cyber Threats
## How Trend Micro Helps Manage Exploited Vulnerabilities
As technological innovations evolve, protecting companies from cyber threats tomorrow secures their businesses today. Read how Trend Micro protects customers from vulnerability exploits by blocking them as early as possible.
By: Jon Clay 2021/04/28 Read time: ( words)
Save to Folio
As technological innovations evolve, protecting companies from cyber threats tomorrow secures their businesses today. Exploiting known vulnerabilities to successfully compromise an organization has long been a common tactic used by malicious actors. Whether Heartbleed, EternalBlue, or most recently Zerologon, threat actors take advantage of newly disclosed vulnerabilities in their attacks. But even with thousands of new vulnerabilities
Trendmicro
Manage Zero Day Exploits (ZDI) with Trend Micro Solutions
blogs_trendmicro·2021-04-28
Manage Zero Day Exploits (ZDI) with Trend Micro Solutions
Minacce cyber
## How Trend Micro Helps Manage Exploited Vulnerabilities
As technological innovations evolve, protecting companies from cyber threats tomorrow secures their businesses today. Read how Trend Micro protects customers from vulnerability exploits by blocking them as early as possible.
By: Jon Clay Apr 28, 2021 Read time: ( words)
Save to Folio
As technological innovations evolve, protecting companies from cyber threats tomorrow secures their businesses today. Exploiting known vulnerabilities to successfully compromise an organization has long been a common tactic used by malicious actors. Whether Heartbleed, EternalBlue, or most recently Zerologon, threat actors take advantage of newly disclosed vulnerabilities in their attacks. But even with thousands of new vulnerabilitie
Trendmicro
Manage Zero Day Exploits (ZDI) with Trend Micro Solutions
blogs_trendmicro·2021-04-28
Manage Zero Day Exploits (ZDI) with Trend Micro Solutions
Ciberamenazas
## How Trend Micro Helps Manage Exploited Vulnerabilities
As technological innovations evolve, protecting companies from cyber threats tomorrow secures their businesses today. Read how Trend Micro protects customers from vulnerability exploits by blocking them as early as possible.
By: Jon Clay Apr 28, 2021 Read time: ( words)
Save to Folio
As technological innovations evolve, protecting companies from cyber threats tomorrow secures their businesses today. Exploiting known vulnerabilities to successfully compromise an organization has long been a common tactic used by malicious actors. Whether Heartbleed, EternalBlue, or most recently Zerologon, threat actors take advantage of newly disclosed vulnerabilities in their attacks. But even with thousands of new vulnerabilitie
Trendmicro
Manage Zero Day Exploits (ZDI) with Trend Micro Solutions
blogs_trendmicro·2021-04-28
Manage Zero Day Exploits (ZDI) with Trend Micro Solutions
Cyber Threats
## How Trend Micro Helps Manage Exploited Vulnerabilities
As technological innovations evolve, protecting companies from cyber threats tomorrow secures their businesses today. Read how Trend Micro protects customers from vulnerability exploits by blocking them as early as possible.
By: Jon Clay Apr 28, 2021 Read time: ( words)
Save to Folio
As technological innovations evolve, protecting companies from cyber threats tomorrow secures their businesses today. Exploiting known vulnerabilities to successfully compromise an organization has long been a common tactic used by malicious actors. Whether Heartbleed, EternalBlue, or most recently Zerologon, threat actors take advantage of newly disclosed vulnerabilities in their attacks. But even with thousands of new vulnerabilitie
Trendmicro
Manage Zero Day Exploits (ZDI) with Trend Micro Solutions
blogs_trendmicro·2021-04-28
Manage Zero Day Exploits (ZDI) with Trend Micro Solutions
Cyber Threats
# How Trend Micro Helps Manage Exploited Vulnerabilities
As technological innovations evolve, protecting companies from cyber threats tomorrow secures their businesses today. Read how Trend Micro protects customers from vulnerability exploits by blocking them as early as possible.
By: Jon Clay
2021/04/28
Read time: ( words)
Save to Folio
Photo credit: pxhere
As technological innovations evolve, protecting companies from cyber threats tomorrow secures their businesses today. Exploiting known vulnerabilities to successfully compromise an organization has long been a common tactic used by malicious actors. Whether Heartbleed, EternalBlue, or most recently Zerologon, threat actors take advantage of newly disclosed vulnerabilities in their attacks. But even with thousands o
Tenable
Government Agencies Warn of State-Sponsored Actors Exploiting Publicly Known Vulnerabilities
blogs_tenable·2020-10-23
Government Agencies Warn of State-Sponsored Actors Exploiting Publicly Known Vulnerabilities
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Qualys
NSA Alert: Chinese State-Sponsored Actors Exploit Known Vulnerabilities | Qualys
blogs_qualys·2020-10-22·CVSS 9.8
CVE-2020-15505 [CRITICAL] NSA Alert: Chinese State-Sponsored Actors Exploit Known Vulnerabilities | Qualys
#### Table of Contents
- Detect 25 Publicly Known Vulnerabilities using VMDR
Update November 25, 2020: The UK National Cyber Security Centre alerts that APT nation-state groups and cybercriminals are exploiting MobileIron RCE vulnerability (CVE-2020-15505).
Original post: On October 20, 2020, the United States National Security Agency (NSA) released a cybersecurity advisory on Chinese state-sponsored malicious cyber activity. The NSA alert provided a list of 25 publicly known vulnerabilities that are known to be recently leveraged by cyber actors for various hacking operations.
“Since these techniques include exploitation of publicly known vulnerabilities, it is critical that network defenders prioritize patching and
mitigation efforts,” said the NSA advisory. It also recommended “crit
Qualys
NSA Alert: Chinese State-Sponsored Actors Exploit Known Vulnerabilities
blogs_qualys·2020-10-22·CVSS 10.0
CVE-2020-15505 [CRITICAL] NSA Alert: Chinese State-Sponsored Actors Exploit Known Vulnerabilities
## Table of Contents
Detect 25 Publicly Known Vulnerabilities using VMDR
Update November 25, 2020 : The UK National Cyber Security Centre alerts that APT nation-state groups and cybercriminals are exploiting MobileIron RCE vulnerability (CVE-2020-15505).
Original post : On October 20, 2020, the United States National Security Agency (NSA) released a cybersecurity advisory on Chinese state-sponsored malicious cyber activity. The NSA alert provided a list of 25 publicly known vulnerabilities that are known to be recently leveraged by cyber actors for various hacking operations.
“Since these techniques include exploitation of publicly known vulnerabilities, it is critical that network defenders prioritize patching and mitigation efforts,” said the NSA advisory. It also recommended “critic
Crowdstrike
What is a Zero-Day Exploit?
blogs_crowdstrike·CVSS 9.8
[CRITICAL] What is a Zero-Day Exploit?
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## "Zero-Day" Definition
The term "Zero-Day" is used when security teams are unaware of their software vulnerability, and they’ve had “0” days to work on a security patch or an update to fix the issue. “Zero-Day” is commonly associated with the terms Vulnerability , Exploit , and Threat . It is important to understand the difference:
A Zero-Day Vulnerability is an unknown security vulnerability or software flaw that a threat actor can target with malicious code.
A Zero-Day Exploit is the technique or tactic a malicious actor uses to leverage the vulnerability to attack a
Crowdstrike
From the Archives: Drop the MIC
blogs_crowdstrike·CVSS 7.5
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Helping Non-Security Stakeholders Understand AT
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What is a Zero-Day Exploit?
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What is a Zero-Day Exploit?
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## "Zero-Day" Definition
The term "Zero-Day" is used when security teams are unaware of their software vulnerability, and they’ve had “0” days to work on a security patch or an update to fix the issue. “Zero-Day” is commonly associated with the terms Vulnerability , Exploit , and Threat . It is important to understand the difference:
A Zero-Day Vulnerability is an unknown security vulnerability or software flaw that a threat actor can target with malicious code.
A Zero-Day Exploit is the technique o
Huntress
CVE-2019-1040 Vulnerability: Analysis, Impact, Mitigation | Huntress
blogs_huntress·CVSS 5.3
CVE-2019-1040 [MEDIUM] CVE-2019-1040 Vulnerability: Analysis, Impact, Mitigation | Huntress
## CVE-2019-1040 Vulnerability
Published:10/07/2025
Written by: Monica Burgess
CVE-2019-1040 is a critical tampering vulnerability found in Microsoft Windows New Technology LAN Manager (NTLM). This flaw allows a man-in-the-middle (MitM) attacker to bypass certain NTLM protections, like Message Integrity Code (MIC), and downgrade NTLM security features. This lets them relay an authentication request to a target server, like one running Exchange or ADFS, and gain access as the authenticated user. Essentially, it’s a way for attackers to slip past security checks and take control.
## When was it Discovered?
The vulnerability was discovered and reported by security researchers Marina Krotofil and Yushkevich. Microsoft issued a patch for CVE-2019-1040 as part of its Patch Tuesday release o
Crowdstrike
What is a Zero-Day Exploit?
blogs_crowdstrike·CVSS 9.8
[CRITICAL] What is a Zero-Day Exploit?
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## "Zero-Day" Definition
The term "Zero-Day" is used when security teams are unaware of their software vulnerability, and they’ve had “0” days to work on a security patch or an update to fix the issue. “Zero-Day” is commonly associated with the terms Vulnerability , Exploit , and Threat . It is important to understand the difference:
A Zero-Day Vulnerability is an unknown security vulnerability or software flaw that a threat actor can target with malicious code.
A Zero-Day Exploit is the technique or tactic a malicious actor uses to leverage the vulnerability to attack a
2019-06-12
Published
Exploited in the wild