dbcve.org
Ios XeOperating system · Cisco

CVE-2024-20510

CRITICAL · 9.3 CVSS v3.1 Published 2024-09-25
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
98/100
Remediation priority · Urgent
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
A vulnerability in the Central Web Authentication (CWA) feature of Cisco IOS XE Software for Wireless Controllers could allow an unauthenticated, adjacent attacker to bypass the pre-authentication access control list (ACL), which could allow access to network resources before user authentication. This vulnerability is due to a logic error when activating the pre-authentication ACL that is received from the authentication, authorization, and accounting (AAA) server. An attacker could exploit this vulnerability by connecting to a wireless network that is configured for CWA and sending traffic through an affected device that should be denied by the configured ACL before user authentication. A successful exploit could allow the attacker to bypass configured ACL protections on the affected device before the user authentication is completed, allowing the attacker to access trusted networks that the device might be protecting.

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 · high confidence

A logic error in Cisco IOS XE Wireless Controllers' Central Web Authentication (CWA) feature causes the pre-authentication ACL received from the AAA server to fail activation, allowing unauthenticated adjacent attackers to bypass ACL protections and access trusted network resources before user authentication completes.

MitigationApply the Cisco IOS XE software update addressing CVE-2024-20510 when released; until then, implement additional network segmentation or manual ACL enforcement at network edge devices to restrict pre-authentication access.

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
Ios XeOperating system
Affected:= 16.3.1= 16.3.1a= 16.3.2= 16.3.3= 16.3.4= 16.3.5= 16.3.5b= 16.3.6= 16.3.7= 16.3.8= 16.3.9= 16.3.10

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
Low
Privileges
None
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
None

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/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. Identify the Cisco IOS XE version
    Run 'show version' or 'show version | include IOS XE' on the device CLI to retrieve the installed software version.
    Affected if The displayed version matches any of these: 16.3.1, 16.3.1a, 16.3.2, 16.3.3, 16.3.4, 16.3.5, 16.3.5b, 16.3.6, 16.3.7, 16.3.8, 16.3.9, or 16.3.10.
  2. Confirm Central Web Authentication is in use
    Run 'show running-config | include cwa' or check for 'central-web-auth' under wireless configuration sections. Also review AAA configuration for 'ip admission' rules referencing CWA.
    Affected if Central Web Authentication (CWA) is enabled and configured on the wireless controller.
  3. Verify pre-authentication ACL configuration from AAA
    Run 'show wireless client summary' and inspect the WLAN/SSID configuration for any 'acl' or 'pre-authentication access-list' settings. Check the AAA server configuration for downloadable ACL (dACL) or static ACL assignments used during pre-authentication.
    Affected if A pre-authentication ACL received from the AAA server is configured but fails to activate properly, indicated by clients bypassing ACL restrictions before authentication completes.
  4. Check for ACL bypass indicators
    Monitor network traffic or review client connection logs for unauthenticated clients accessing trusted network resources. Use 'show client detail' to inspect client state and verify ACL application status.
    Affected if Unauthenticated clients can reach trusted network segments despite a pre-authentication ACL being configured.

You are affected if your Cisco IOS XE version is 16.3.1 through 16.3.10 and Central Web Authentication with a pre-authentication ACL from AAA is enabled, with evidence of unauthenticated clients bypassing ACL protections.

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
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply the Cisco IOS XE software update addressing CVE-2024-20510 when released; until then, implement additional network segmentation or manual ACL enforcement at network edge devices to restrict pre-authentication access.

Fix this in Ios Xe Scoped from the published advisory
  • Consultation4.0 h
  • Implementation6.0 h
  • Testing8.0 h
  • Review / QA3.0 h
21.0 hours of engineering $3,620
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,792.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2024-20510 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2024-20510 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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