How severe is CVE-2016-9221?

CVE-2016-9221 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.

Is CVE-2016-9221 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (42nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2016-9221?

CVE-2016-9221 primarily affects Cisco Aironet Access Point Software. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2016-9221?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2016-9221 published?

CVE-2016-9221 was published on 2017-01-26 and last updated on 2026-06-17.

CVE-2016-9221

CVE-2016-9221 is a medium-severity vulnerability in Cisco Aironet Access Point Software with a CVSS 3.x base score of 4.3. 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-399.

Key facts

Severity: Medium (CVSS 3.x base score 4.3)
CVSS v2: 3.3
EPSS exploit prediction: 1% (42nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-399
Affected product: Cisco Aironet Access Point Software
Published: 2017-01-26
Last modified: 2026-06-17

Description

A Denial of Service Vulnerability in 802.11 ingress connection authentication handling for the Cisco Mobility Express 2800 and 3800 Access Points (APs) could allow an unauthenticated, adjacent attacker to cause authentication to fail. Affected Products: This vulnerability affects Cisco Mobility Express 2800 Series and 3800 Series Access Points when configured in local mode in 40 MHz. More Information: CSCvb33575. Known Affected Releases: 8.2(121.12) 8.4(1.82). Known Fixed Releases: 8.2(131.2) 8.2(131.3) 8.2(131.4) 8.2(141.0) 8.3(104.53) 8.3(104.54) 8.4(1.80) 8.4(1.85).

Frequently asked questions

What is CVE-2016-9221?: A Denial of Service Vulnerability in 802.11 ingress connection authentication handling for the Cisco Mobility Express 2800 and 3800 Access Points (APs) could allow an unauthenticated, adjacent attacker to cause authentication to fail. Affected Products: This vulnerability affects Cisco Mobility Express 2800 Series and 3800 Series Access Points when configured in local mode in 40 MHz. More Information: CSCvb33575. Known Affected Releases: 8.2(121.12) 8.4(1.82). Known Fixed Releases: 8.2(131.2) 8.2(131.3) 8.2(131.4) 8.2(141.0) 8.3(104.53) 8.3(104.54) 8.4(1.80) 8.4(1.85).
How severe is CVE-2016-9221?: CVE-2016-9221 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.
Is CVE-2016-9221 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (42nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2016-9221?: CVE-2016-9221 primarily affects Cisco Aironet Access Point Software. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2016-9221?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2016-9221 published?: CVE-2016-9221 was published on 2017-01-26 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:o:cisco:aironet_access_point_software:8.2\(121.12\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:aironet_access_point_software:8.4\(1.82\):*:*:*:*:*:*:*

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Other CWE-399 (Resource Management Errors) vulnerabilities

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CVE-2015-0335 — Critical (CVSS 10.0): Adobe Flash Player before 13.0.0.277 and 14.x through 17.x before 17.0.0.134 on Windows and OS X and before…
CVE-2015-0333 — Critical (CVSS 10.0): Adobe Flash Player before 13.0.0.277 and 14.x through 17.x before 17.0.0.134 on Windows and OS X and before…
CVE-2014-4121 — Critical (CVSS 10.0): Microsoft .NET Framework 2.0 SP2, 3.5, 3.5.1, 4, 4.5, 4.5.1, and 4.5.2 does not properly parse internationalized…
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