CVE-2017-3873

CVE-2017-3873 is a high-severity vulnerability in Cisco Aironet Access Point Firmware with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-20.

Key facts

Description

A vulnerability in the Plug-and-Play (PnP) subsystem of the Cisco Aironet 1800, 2800, and 3800 Series Access Points running a Lightweight Access Point (AP) or Mobility Express image could allow an unauthenticated, adjacent attacker to execute arbitrary code with root privileges. The vulnerability is due to insufficient validation of PnP server responses. The PnP feature is only active while the device does not contain a configuration, such as a first time boot or after a factory reset has been issued. An attacker with the ability to respond to PnP configuration requests from the affected device can exploit the vulnerability by returning malicious PnP responses. If a Cisco Application Policy Infrastructure Controller - Enterprise Module (APIC-EM) is available on the network, the attacker would need to exploit the issue in the short window before a valid PnP response was received. If successful, the attacker could gain the ability to execute arbitrary code with root privileges on the underlying operating system of the device. Cisco has confirmed that the only vulnerable software version is 8.3.102.0. Cisco Bug IDs: CSCvb42386.

Frequently asked questions

What is CVE-2017-3873?
A vulnerability in the Plug-and-Play (PnP) subsystem of the Cisco Aironet 1800, 2800, and 3800 Series Access Points running a Lightweight Access Point (AP) or Mobility Express image could allow an unauthenticated, adjacent attacker to execute arbitrary code with root privileges. The vulnerability is due to insufficient validation of PnP server responses. The PnP feature is only active while the device does not contain a configuration, such as a first time boot or after a factory reset has been issued. An attacker with the ability to respond to PnP configuration requests from the affected device can exploit the vulnerability by returning malicious PnP responses. If a Cisco Application Policy Infrastructure Controller - Enterprise Module (APIC-EM) is available on the network, the attacker would need to exploit the issue in the short window before a valid PnP response was received. If successful, the attacker could gain the ability to execute arbitrary code with root privileges on the underlying operating system of the device. Cisco has confirmed that the only vulnerable software version is 8.3.102.0. Cisco Bug IDs: CSCvb42386.
How severe is CVE-2017-3873?
CVE-2017-3873 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over an adjacent network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2017-3873 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (50th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2017-3873?
CVE-2017-3873 affects Cisco Aironet Access Point Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2017-3873?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2017-3873 published?
CVE-2017-3873 was published on 2017-05-16 and last updated on 2026-06-17.

References

Affected products (1)

More vulnerabilities in Cisco Aironet Access Point Firmware

All CVEs affecting Cisco Aironet Access Point Firmware →

Other CWE-20 (Improper Input Validation) vulnerabilities

Browse all CWE-20 (Improper Input Validation) vulnerabilities →