CVE-2021-1623 Denial of service in Cisco IOS XE Software

High 7.7 Published 23 Sep 2021 Updated 7 Nov 2024

An authenticated remote attacker can cause a denial of service on Cisco cBR-8 routers by overwhelming the SNMP punt path with excessive requests.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2021-1623?

CVE-2021-1623 is a high-severity denial of service vulnerability in Cisco Ios Xe, published on 23 Sep 2021. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

A vulnerability in the Simple Network Management Protocol (SNMP) punt handling function of Cisco cBR-8 Converged Broadband Routers could allow an authenticated, remote attacker to overload a device punt path, resulting in a denial of service (DoS) condition. This vulnerability is due to the punt path being overwhelmed by large quantities of SNMP requests. An attacker could exploit this vulnerability by sending a large number of SNMP requests to an affected device. A successful exploit could allow the attacker to overload the device punt path, resulting in a DoS condition.

Weakness: CWE-399

Which versions are affected by CVE-2021-1623?

It affects 1 product.

Products include Cisco Ios Xe.

How do I fix CVE-2021-1623?

No fix has been published for CVE-2021-1623 yet. Limit exposure of the affected software until one is available.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2021-1623 being exploited?

There is no known exploitation of CVE-2021-1623 in the wild and no public exploit code.

All Cisco Ios Xe vulnerabilities

Sources

Also known as GHSA-x762-73p7-hfjc.