CVE-2020-3399
CVE-2020-3399 is a high-severity vulnerability in Cisco Ios Xe with a CVSS 3.x base score of 8.6. 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-125.
Key facts
- Severity: High (CVSS 3.x base score 8.6)
- CVSS v2: 7.8
- EPSS exploit prediction: 1% (68th percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-125
- Affected product: Cisco Ios Xe
- Published:
- Last modified:
Description
A vulnerability in the Control and Provisioning of Wireless Access Points (CAPWAP) protocol processing of Cisco IOS XE Software for Cisco Catalyst 9800 Series Wireless Controllers could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition of an affected device. The vulnerability is due to insufficient input validation during CAPWAP packet processing. An attacker could exploit this vulnerability by sending a crafted CAPWAP packet to an affected device, resulting in a buffer over-read. A successful exploit could allow the attacker to cause the affected device to crash and reload, resulting in a DoS condition on the affected device.
Frequently asked questions
- What is CVE-2020-3399?
- A vulnerability in the Control and Provisioning of Wireless Access Points (CAPWAP) protocol processing of Cisco IOS XE Software for Cisco Catalyst 9800 Series Wireless Controllers could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition of an affected device. The vulnerability is due to insufficient input validation during CAPWAP packet processing. An attacker could exploit this vulnerability by sending a crafted CAPWAP packet to an affected device, resulting in a buffer over-read. A successful exploit could allow the attacker to cause the affected device to crash and reload, resulting in a DoS condition on the affected device.
- How severe is CVE-2020-3399?
- CVE-2020-3399 has a CVSS 3.x base score of 8.6, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
- Is CVE-2020-3399 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (68th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2020-3399?
- CVE-2020-3399 primarily affects Cisco Ios Xe. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
- How do I fix CVE-2020-3399?
- 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-2020-3399 published?
- CVE-2020-3399 was published on 2020-09-24 and last updated on 2026-06-17.
References
Affected products (3)
- cpe:2.3:o:cisco:ios_xe:16.12:*:*:*:*:*:*:*
- cpe:2.3:o:cisco:ios_xe:16.12.1s:*:*:*:*:*:*:*
- cpe:2.3:o:cisco:ios_xe:16.12.2:*:*:*:*:*:*:*
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