CVE-2021-3816Public exploitNetwork attack vector

Administrative page alteration via unescaped group prefix

Published Jan 19, 2022 · Updated Aug 3, 2024

Stored HTML injection in Cacti 1.1.38 allows remote authenticated users with User Management permission to alter administrative pages. The user_group_admin.php Copy path bypasses input validation, stores group_prefix content, and renders it without HTML escaping on the deletion view. Exploitation requires User Management permission and a later visit to the affected group view; demonstrated impact is persistent markup injection.

CVSS severity5.4
Medium
EPSS probability0.53%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored HTML injection in Cacti 1.1.38 allows remote authenticated users with User Management permission to alter administrative pages. The user_group_admin.php Copy path bypasses input validation, stores group_prefix content, and renders it without HTML escaping on the deletion view. Exploitation requires User Management permission and a later visit to the affected group view; demonstrated impact is persistent markup injection.

The record

CVE
CVE-2021-3816
Published
Jan 19, 2022
Updated
Aug 3, 2024
Vendor
The Cacti Group
Product
Cacti
Classifications
CWE-79, T1203
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 19, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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=1.1.38

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

The Cacti Group · Cactiversion=1.1.38

Published CVSS scores

3.5NVDAV:N/AC:M/Au:S/C:N/I:P/A:N
5.4NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/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.

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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)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1203Exploitation for Client Execution

Public exploit references

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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