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Vulnerability record · CVE-2021-1439 · published 24 March 2021

CVE-2021-1439: Cisco aironet access point software classic buffer overflow vulnerability

Cisco · Aironet Access Point Software

A vulnerability in the multicast DNS (mDNS) gateway feature of Cisco Aironet Series Access Points Software could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to insufficient input validation of incoming mDNS traffic. An attacker could exploit this vulnerability by sending a crafted mDNS packet to an affected device through a wireless network that is configured in FlexConnect local switching mode or through a wired network on a configured mDNS VLAN. A successful exploit could allow the attacker to cause the access point (AP) to reboot, resulting in a DoS condition.

7.4 CVSS 3.1 High EPSS 0.39% · top 69.6% CWE-120 · Classic buffer overflow
7.4CVSS 3.1 base score, v2 3.3
0.39%EPSS exploitation probability, 30 days
NoNot in CISA KEV
2Affected product versions listed by NVD
2References
17 Jun 2026Last modified by NVD

Description

A vulnerability in the multicast DNS (mDNS) gateway feature of Cisco Aironet Series Access Points Software could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to insufficient input validation of incoming mDNS traffic. An attacker could exploit this vulnerability by sending a crafted mDNS packet to an affected device through a wireless network that is configured in FlexConnect local switching mode or through a wired network on a configured mDNS VLAN. A successful exploit could allow the attacker to cause the access point (AP) to reboot, resulting in a DoS condition.

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

Affected products

2 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-aironet-mdns-dos-E6KwYuMx Vendor Advisory
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-aironet-mdns-dos-E6KwYuMx Vendor Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2021-1439), CISA KEV, FIRST EPSS (scores of 2026-10-05). This page is refreshed as NVD updates the record.