dbcve.org
WarpApplication · Cloudflare

CVE-2023-2754

MEDIUM · 6.8 CVSS v3.1 Published 2023-08-03
Fix available
A fix is available. Upgrade to 2023.7.160.0 or later.
See remediation →
73/100
Remediation priority · Elevated
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
The Cloudflare WARP client for Windows assigns loopback IPv4 addresses for the DNS Servers, since WARP acts as local DNS server that performs DNS queries in a secure manner, however, if a user is connected to WARP over an IPv6-capable network, te WARP client did not assign loopback IPv6 addresses but Unique Local Addresses, which under certain conditions could point towards unknown devices in the same local network which enables an Attacker to view DNS queries made by the device.

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

The Cloudflare WARP client for Windows assigns loopback IPv4 addresses (127.0.0.1) for its local DNS service, which is correct. However, for IPv6-capable networks, the client assigns Unique Local Addresses (ULAs) instead of IPv6 loopback addresses (::1). These ULAs can resolve to other devices on the local network, enabling an attacker on the same network to observe DNS queries made by the user's device, exposing query metadata.

MitigationEnsure Cloudflare WARP client is updated to the patched version that assigns IPv6 loopback addresses instead of Unique Local Addresses; network administrators may also consider network segmentation to limit exposure from local attackers.

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
WarpApplication
Affected:< 2023.7.160.0

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
Adjacent
Complexity
High
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None

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

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. Verify Cloudflare WARP is installed
    Check for the presence of Cloudflare WARP client in the system. Inspect the Windows Registry under HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\ or look for the installation directory (typically C:\Program Files\Cloudflare\WARP\)
    Affected if Cloudflare WARP client is installed on the system
  2. Identify installed WARP version
    Open Windows Settings > Apps > Apps & features, locate Cloudflare WARP, and note the version number displayed. Alternatively, run 'warp-cli --version' from command line if the CLI tool is installed.
    Affected if Installed version is less than 2023.7.160.0
  3. Check IPv6 address bound to local DNS service
    When WARP is running and IPv6 is active on the network, run 'ipconfig /all' and examine the DNS server addresses configured on active network adapters. Look for Unique Local Addresses (fd00::/8 or fd02::/8 prefix) assigned as DNS servers instead of the loopback address ::1.
    Affected if IPv6 DNS configuration shows a ULA (such as fd00::, fd02::, or similar fdxx:: addresses) instead of ::1 as the DNS server for any active adapter
  4. Confirm IPv6 is enabled on network adapter
    Run 'netsh interface ipv6 show interface' to list IPv6-enabled adapters. Ensure IPv6 is enabled on at least one active network adapter (Status = Connected).
    Affected if IPv6 is enabled on a network adapter and the DNS server shows a ULA address rather than ::1

A system is affected if Cloudflare WARP version is below 2023.7.160.0 AND IPv6 is enabled on any network adapter AND the DNS configuration displays a Unique Local Address (ULA) instead of the expected IPv6 loopback address ::1.

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.

dbcve · scoped
Upgrade available Upgrade to 2023.7.160.0 or later
Fixed in 2023.7.160.0
Interim mitigation

Ensure Cloudflare WARP client is updated to the patched version that assigns IPv6 loopback addresses instead of Unique Local Addresses; network administrators may also consider network segmentation to limit exposure from local attackers.

Recommended fix High confidence

WARP client version 2023.7.160.0 or later

  1. Check current WARP client version by opening the WARP application and navigating to Settings > About, or by right-clicking the WARP system tray icon and selecting 'About Cloudflare WARP'
  2. Download the latest WARP client version from the official Cloudflare download page at install.appcenter.ms or from the Cloudflare GitHub releases repository
  3. Run the installer and follow the on-screen prompts to update the WARP client to version 2023.7.160.0 or later
  4. Verify the update was successful by checking that the WARP client now shows version 2023.7.160.0 or higher in the About section
  5. Restart the WARP client if it does not automatically restart after the update

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Warp Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing2.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,060
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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-2023-2754 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