CVE-2021-27180Public exploitNetwork attack vector

Victim-privileged actions via reflected GET input

Published Apr 14, 2021 · Updated Aug 3, 2024

Reflected XSS in MDaemon Webmail before 20.0.4 allows remote attackers to perform actions with a victim user's privileges via a crafted GET request. WorldClient reflects attacker-controlled GET input into a page without neutralizing script-capable content; published sources do not identify the parameter or function. Execution requires an attacked user to open the crafted URL, after which the script can issue Webmail actions under that user's session.

CVSS severity6.1
Medium
EPSS probability0.93%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reflected XSS in MDaemon Webmail before 20.0.4 allows remote attackers to perform actions with a victim user's privileges via a crafted GET request. WorldClient reflects attacker-controlled GET input into a page without neutralizing script-capable content; published sources do not identify the parameter or function. Execution requires an attacked user to open the crafted URL, after which the script can issue Webmail actions under that user's session.

The record

CVE
CVE-2021-27180
Published
Apr 14, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-79, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 14, 2021CVE 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?

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

6.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
4.3NIST NVDAV:N/AC:M/Au:N/C:N/I:P/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')
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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