CVE-2020-3408
HIGHCisco IOS and IOS XE - Unauthenticated Denial of Service via Split DNS Regex Timeout
Title source: llmDescription
A vulnerability in the Split DNS feature of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition. The vulnerability occurs because the regular expression (regex) engine that is used with the Split DNS feature of affected releases may time out when it processes the DNS name list configuration. An attacker could exploit this vulnerability by trying to resolve an address or hostname that the affected device handles. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.
References (1)
Core 1
Core References
Vendor Advisory vendor-advisory
x_refsource_cisco
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-splitdns-SPWqpdGW
Scores
CVSS v3
8.6
EPSS
0.0116
EPSS Percentile
78.8%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
yes
Technical Impact
partial
Details
CWE
CWE-400
CWE-185
Status
published
Products (2)
cisco/ios
15.8\(3\)m3
cisco/ios_xe
15.8\(3\)m3
Published
Sep 24, 2020
Tracked Since
Feb 18, 2026