CVE-2021-1601

Configuration changes via unrestricted IPv6 packet forwarding

Published Jul 22, 2021 · Updated Nov 7, 2024

Improper access control in Cisco Intersight Virtual Appliance 1.0.9-184 through 1.0.9-291 allows remote attackers to change configuration. The external management interface forwards crafted IPv6 traffic without sufficient packet restrictions, exposing sensitive internal services. The attack requires adjacent network access but no authentication and permits internal-service access and configuration changes.

CVSS severity8.3
High
EPSS probability0.40%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper access control in Cisco Intersight Virtual Appliance 1.0.9-184 through 1.0.9-291 allows remote attackers to change configuration. The external management interface forwards crafted IPv6 traffic without sufficient packet restrictions, exposing sensitive internal services. The attack requires adjacent network access but no authentication and permits internal-service access and configuration changes.

The record

CVE
CVE-2021-1601
Published
Jul 22, 2021
Updated
Nov 7, 2024
Vendor
ClamAV
Product
Cisco Intersight Virtual Appliance
Classifications
CWE-284, T1190
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 22, 2021CVE publishedPublication date reported by the CVE source.
  2. Nov 7, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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  1. Affected versionversion=n/a

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

ClamAV · Cisco Intersight Virtual Applianceversion=n/a

Published CVSS scores

8.3CiscoCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:H/E:X/RL:X/RC:X

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-284Improper Access Control
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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