Aironet 1810 FirmwareOperating system · Cisco
CVE-2019-15261
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 · uneditedA vulnerability in the Point-to-Point Tunneling Protocol (PPTP) VPN packet processing functionality in Cisco Aironet Access Points (APs) could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition. The vulnerability is due to insufficient validation of Generic Routing Encapsulation (GRE) frames that pass through the data plane of an affected AP. An attacker could exploit this vulnerability by associating to a vulnerable AP, initiating a PPTP VPN connection to an arbitrary PPTP VPN server, and sending a malicious GRE frame through the data plane of the AP. A successful exploit could allow the attacker to cause an internal process of the targeted AP to crash, which in turn would cause the AP to reload. The AP reload would cause a DoS condition for clients that are associated with the AP.
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 confidenceA vulnerability in the PPTP VPN packet processing of Cisco Aironet Access Points allows an unauthenticated remote attacker to cause a denial of service. The issue stems from insufficient validation of GRE frames passing through the AP's data plane. An attacker associates with the vulnerable AP, initiates a PPTP VPN connection, and sends a malicious GRE frame that crashes an internal process, causing the AP to reload and disconnect all clients.
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
Aironet 1810 FirmwareOperating system
>= 8.4, < 8.5.151.0>= 8.8, < 8.8.125.0>= 8.9, < 8.9.111.0
Aironet 1830 FirmwareOperating system
>= 8.4, < 8.5.151.0>= 8.8, < 8.8.125.0>= 8.9, < 8.9.111.0
Aironet 1850 FirmwareOperating system
>= 8.4, < 8.5.151.0>= 8.8, < 8.8.125.0>= 8.9, < 8.9.111.0CVSS 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
- Changed
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/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 checksWork through these to decide whether this CVE applies to you.
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Identify the Cisco Aironet AP modelLog into the AP controller or access point CLI and run 'show version' or check the AP model number from the management interfaceAffected if The model is a Cisco Aironet 1810, 1830, or 1850
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Check the installed firmware versionRun 'show version' on the AP or AP controller to retrieve the firmware version stringAffected if The firmware version falls within any of these ranges: 8.4 to below 8.5.151.0, 8.8 to below 8.8.125.0, or 8.9 to below 8.9.111.0
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Verify if PPTP VPN is enabledCheck the AP or controller configuration for PPTP or GRE tunnel settings using 'show running-config' or the web management interfaceAffected if PPTP VPN functionality or GRE tunneling is configured and active on the AP
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Check for recent reloads or crash logsRun 'show reload' or 'show crash' on the AP controller to view reload history and any crash logsAffected if The AP has reloaded unexpectedly or crash logs contain GRE-related errors
The AP is affected if it is a model 1810/1830/1850 running a firmware version within the affected ranges AND PPTP VPN is enabled, which would allow a connected attacker to trigger a DoS via malicious GRE frames.
Generated from the published advisory. Verify against your own configuration.
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 data8.5.151.08.8.125.08.9.111.0
Apply the Cisco firmware update for CVE-2019-15261. If no patch is available, disable PPTP VPN functionality on affected APs or implement network-level filtering to block malicious GRE traffic.
Fix this in Aironet 1810 Firmware
Scoped from the published advisory
- Consultation4.0 h
- Implementation6.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,544.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2019-15261 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2019-15261 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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