CVE-2021-42558Public exploitNetwork attack vector

Browser code execution via unsanitized interface fields

Published Jan 12, 2022 · Updated Aug 4, 2024

Cross-site scripting in MITRE CALDERA 2.8.1 and earlier allows remote attackers to execute JavaScript in a user's browser. The web interface renders unsanitized agent beacon fields, operation names, objective and source values, Human plugin names, and Compass imports into HTML. An unauthenticated crafted beacon can persist code for an authenticated operator viewing Agents, while other documented paths require authenticated access or opening attacker-controlled content.

CVSS severity6.1
Medium
EPSS probability1.05%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site scripting in MITRE CALDERA 2.8.1 and earlier allows remote attackers to execute JavaScript in a user's browser. The web interface renders unsanitized agent beacon fields, operation names, objective and source values, Human plugin names, and Compass imports into HTML. An unauthenticated crafted beacon can persist code for an authenticated operator viewing Agents, while other documented paths require authenticated access or opening attacker-controlled content.

The record

CVE
CVE-2021-42558
Published
Jan 12, 2022
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-79, CAPEC-592, CAPEC-591, T1059.007
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 12, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

4.3NIST NVDAV:N/AC:M/Au:N/C:N/I:P/A:N
6.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/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.

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 exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CAPEC-592Stored XSS
CAPEC-591Reflected XSS
T1059.007Command and Scripting Interpreter: JavaScript/JScript

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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