Resource exhaustion in Cisco 1100-4g Integrated Services Router

CVE-2020-3408

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.

EPSS: 0.016 (73.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.6 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2020-3408?
CVE-2020-3408 is a high-severity vulnerability in Cisco 1100-4g Integrated Services Router, classified under Incorrect Regular Expression. CVSS score: 8.6/10. Published 2020-09-24.
How severe is CVE-2020-3408?
High severity. CVSS v3 base score is 8.6 out of 10.
Is CVE-2020-3408 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.