CVE-2021-1623

Cisco IOS XE Software for Cisco cBR-8 Converged Broadband Routers Simple Network Management Protocol Denial of Service Vulnerability

HIGH
7.7
CVSS Score
Published: September 23, 2021 at 02:25 AM UTC
Updated: June 17, 2026 at 03:32 AM UTC
2 products affected across 1 vendorIOS XeCbr-8

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Severity
HIGH7.7
Exploit prediction
EPSS 1%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 17.6.1a
Affected range stops below 17.6.1a, so it looks safe — our inference, not a vendor statement
cisco-cbr-8 (environment)
80%
All versions

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.7HIGHcisco
Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
CHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-399NVD-CWE-noinfo

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