CVE-2021-41824Network attack vector

Spreadsheet formula execution via unneutralized CSV fields

Published Sep 29, 2021 · Updated Aug 4, 2024

CSV injection in Craft CMS 3.4.0 through 3.7.13 allows remote attackers to place spreadsheet formulas in exported element data. CsvResponseFormatter writes scalar fields beginning with =, -, +, or @ directly to CSV output without neutralizing them. Exploitation requires untrusted element data, an element-index export, and a user who opens the CSV in an older Excel version, where the formula payload executes.

CVSS severity8.8
High
EPSS probability1.37%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

CSV injection in Craft CMS 3.4.0 through 3.7.13 allows remote attackers to place spreadsheet formulas in exported element data. CsvResponseFormatter writes scalar fields beginning with =, -, +, or @ directly to CSV output without neutralizing them. Exploitation requires untrusted element data, an element-index export, and a user who opens the CSV in an older Excel version, where the formula payload executes.

The record

CVE
CVE-2021-41824
Published
Sep 29, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-1236, T1204.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 29, 2021CVE 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

6.8NIST NVDAV:N/AC:M/Au:N/C:P/I:P/A:P
8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

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-1236Improper Neutralization of Formula Elements in a CSV File
T1204.002Malicious File

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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