CVE-2021-1396Network attack vector

Unauthenticated disclosure and configuration changes via underprotected API

Published Feb 24, 2021 · Updated Nov 8, 2024

Missing authentication in Cisco Application Services Engine 1.1(3d) and earlier allows remote attackers to access a Data Network API. Insufficient access controls let crafted HTTP requests reach the API without credentials and expose device-specific information or permit limited configuration changes. The API must be reachable on the Data Network; successful requests can also create tech support files in an isolated volume but do not affect availability.

CVSS severity6.5
Medium
EPSS probability1.04%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Missing authentication in Cisco Application Services Engine 1.1(3d) and earlier allows remote attackers to access a Data Network API. Insufficient access controls let crafted HTTP requests reach the API without credentials and expose device-specific information or permit limited configuration changes. The API must be reachable on the Data Network; successful requests can also create tech support files in an isolated volume but do not affect availability.

The record

CVE
CVE-2021-1396
Published
Feb 24, 2021
Updated
Nov 8, 2024
Vendor
ClamAV
Product
Cisco Application Services Engine
Classifications
CWE-306, T1210
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 24, 2021CVE publishedPublication date reported by the CVE source.
  2. Nov 8, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=n/a

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

ClamAV · Cisco Application Services Engineversion=n/a

Published CVSS scores

6.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
6.5Cisco Systems, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

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

Weakness, pattern, technique

CWE-306Missing Authentication for Critical Function
T1210Exploitation of Remote Services

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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