CVE-2021-29274Network attack vector

Cross-site scripting via unsanitized issue subject

Published Mar 29, 2021 · Updated Aug 3, 2024

Cross-site scripting in Redmine 4.1.0 through 4.1.1 allows remote attackers to inject script through issue subjects in inline autocomplete. The autocomplete tip renders HTML from an issue subject without sanitization, turning a crafted subject into executable markup when another issue references it. Exploitation requires a victim to view the affected autocomplete result; the consequence is client-side script execution with the victim's Redmine session context.

CVSS severity6.1
Medium
EPSS probability0.83%
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 Redmine 4.1.0 through 4.1.1 allows remote attackers to inject script through issue subjects in inline autocomplete. The autocomplete tip renders HTML from an issue subject without sanitization, turning a crafted subject into executable markup when another issue references it. Exploitation requires a victim to view the affected autocomplete result; the consequence is client-side script execution with the victim's Redmine session context.

The record

CVE
CVE-2021-29274
Published
Mar 29, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-79, T1189
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 29, 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

6.1NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
4.3NVDAV: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 exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1189Drive-by Compromise

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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