CVE-2021-33256Public exploitNetwork attack vector

Command execution via CSV formula injection

Published Aug 9, 2021 · Updated Aug 3, 2024

CSV injection in ManageEngine ADSelfService Plus 6.1 build 6101 allows unauthenticated attackers to execute commands via exported audit CSV files. The j_username value is stored in the User Attempts Audit Report without neutralizing spreadsheet formulas, so a privileged administrator who exports and opens the CSV can trigger a reverse shell. The vendor disputes that this behavior constitutes a security issue, and exploitation requires that privileged export and file-opening interaction.

CVSS severity8.8
High
EPSS probability79.00%
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 ManageEngine ADSelfService Plus 6.1 build 6101 allows unauthenticated attackers to execute commands via exported audit CSV files. The j_username value is stored in the User Attempts Audit Report without neutralizing spreadsheet formulas, so a privileged administrator who exports and opens the CSV can trigger a reverse shell. The vendor disputes that this behavior constitutes a security issue, and exploitation requires that privileged export and file-opening interaction.

The record

CVE
CVE-2021-33256
Published
Aug 9, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-1236, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 9, 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

8.8NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
9.3NVDAV:N/AC:M/Au:N/C:C/I:C/A:C

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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-1236Improper Neutralization of Formula Elements in a CSV File
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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