CVE-2019-15261 Cisco Aironet Access Points Point-to-Point Tunneling Protocol Denial of Service Vulnerability

What is CVE-2019-15261?

CVE-2019-15261 is a high-severity denial of service vulnerability in Cisco Aironet Access Point Software, published on 16 Oct 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

A 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.

Weakness: CWE-20

Which versions are affected by CVE-2019-15261?

It affects 3 products.

Products include Cisco Aironet 1810 Firmware, Cisco Aironet 1830 Firmware, Cisco Aironet 1850 Firmware.

How do I fix CVE-2019-15261?

No fix has been published for CVE-2019-15261 yet. Limit exposure of the affected software until one is available.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2019-15261 being exploited?

There is no known exploitation of CVE-2019-15261 in the wild and no public exploit code.

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-3273-9gqr-v74w.