CVE-2020-3421
Multiple vulnerabilities in the Zone-Based Firewall feature of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause the device to reload or stop forwarding traffic through the firewall.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.93%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
Multiple vulnerabilities in the Zone-Based Firewall feature of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause the device to reload or stop forwarding traffic through the firewall. The vulnerabilities are due to incomplete handling of Layer 4 packets through the device. An attacker could exploit these vulnerabilities by sending a certain sequence of traffic patterns through the device. A successful exploit could allow the attacker to cause the device to reload or stop forwarding traffic through the firewall, resulting in a denial of service. For more information about these vulnerabilities, see the Details section of this advisory.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 1.93% probability · 79th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-754
- Affected
- cisco/ios xe
- Source
- psirt@cisco.com
References
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.