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Active ResponseApplication · Mcafee

CVE-2019-3643

HIGH · 7.5 CVSS v3.1 Published 2019-09-11
Fix available
A fix is available. Upgrade to 7.7.2.24 / 7.8.2.13 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
McAfee Web Gateway (MWG) earlier than 7.8.2.13 is vulnerable to a remote attacker exploiting CVE-2019-9511, potentially leading to a denial of service. This affects the scanning proxies.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

McAfee Web Gateway versions prior to 7.8.2.13 contain a vulnerability in their scanning proxy components that allows remote attackers to exploit CVE-2019-9511 (an HTTP/2 denial of service vulnerability). Attackers can potentially crash the scanning proxies by manipulating HTTP/2 stream multiplexing, causing a denial of service condition.

MitigationUpgrade McAfee Web Gateway to version 7.8.2.13 or later to remediate this vulnerability. If immediate upgrading is not possible, consider rate limiting or restricting HTTP/2 traffic to the scanning proxies as a temporary mitigation.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Active ResponseApplication
Affected:= 1.0.0= 1.1.0= 2.0= 2.0.1= 2.1= 2.2= 2.3= 2.4
Advanced Threat DefenseApplication
Affected:= 4.0= 4.2= 4.4= 4.6
Enterprise Security ManagerApplication
Affected:= 10.2.0= 10.3.4= 10.4.0= 11.0.0= 11.1.0= 11.1.1= 11.1.2= 11.1.3= 11.2.0
Web GatewayApplication
Affected:>= 7.7.2.0, < 7.7.2.24>= 7.8.2, < 7.8.2.13>= 8.0.0, < 8.2.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify the installed McAfee product
    Review your system inventory or check installed McAfee software to determine which product is in use: McAfee Web Gateway, McAfee Active Response, McAfee Advanced Threat Defense, or McAfee Enterprise Security Manager.
    Affected if Any of the four listed products is installed.
  2. Determine the product version
    Use the product's admin console, command line interface, or check the installed software version. For Web Gateway, this is typically visible in the admin UI under System > Status or via 'mwg-version' command if available.
    Affected if Version cannot be determined or does not match the affected ranges.
  3. Verify the version is within an affected range
    Compare your installed version against these affected ranges: Active Response = 1.0.0, 1.1.0, 2.0, 2.0.1, 2.1, 2.2, 2.3, 2.4; Advanced Threat Defense = 4.0, 4.2, 4.4, 4.6; Enterprise Security Manager = 10.2.0, 10.3.4, 10.4.0, 11.0.0, 11.1.0, 11.1.1, 11.1.2, 11.1.3, 11.2.0; Web Gateway = 7.7.2.0 to 7.7.2.23, 7.8.2.0 to 7.8.2.12, or 8.0.0 to 8.1.x.
    Affected if The installed version exactly matches one of the listed versions or falls within the Web Gateway ranges.
  4. For Web Gateway, confirm scanning proxy is enabled
    In the Web Gateway admin console, navigate to Policy > Proxy Settings or scanning configuration. Verify if the scanning proxy component (HTTP/2 scanning or proxy service) is active and handling HTTP/2 traffic.
    Affected if Scanning proxy is enabled and the product version is affected.

A user is affected if they have any of the listed McAfee products at the specified versions, particularly McAfee Web Gateway with scanning proxy enabled handling HTTP/2 traffic.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Upgrade available Upgrade to 7.7.2.24 / 7.8.2.13 / 8.2.0 or later
Fixed in 7.7.2.247.8.2.138.2.0
Interim mitigation

Upgrade McAfee Web Gateway to version 7.8.2.13 or later to remediate this vulnerability. If immediate upgrading is not possible, consider rate limiting or restricting HTTP/2 traffic to the scanning proxies as a temporary mitigation.

Fix this in Active Response Scoped from the published advisory
  • Consultation1.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,040
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,664.

Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2019-3643 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data