CVE-2021-3992Public exploitNetwork attack vector

Authenticated invoice disclosure via unchecked customer identifiers

Published Dec 1, 2021 · Updated Aug 3, 2024

Improper access control in Kimai before 1.16.2 allows remote authenticated users to read unauthorized customer invoice data. The invoice preview and creation routes accepted a customer identifier without checking the account's access to that customer, while form queries could preselect otherwise hidden customer IDs. A low-privileged account with invoice permissions can exploit the flaw over the network to disclose invoice data belonging to customers outside its assigned teams.

CVSS severity6.5
Medium
EPSS probability1.03%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper access control in Kimai before 1.16.2 allows remote authenticated users to read unauthorized customer invoice data. The invoice preview and creation routes accepted a customer identifier without checking the account's access to that customer, while form queries could preselect otherwise hidden customer IDs. A low-privileged account with invoice permissions can exploit the flaw over the network to disclose invoice data belonging to customers outside its assigned teams.

The record

CVE
CVE-2021-3992
Published
Dec 1, 2021
Updated
Aug 3, 2024
Vendor
Kevin Papst
Product
Kimai
Classifications
CWE-639, CWE-284, T1213
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 1, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <1.16.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Kevin Papst · Kimaiversion=unspecified <1.16.2

Published CVSS scores

4.0NIST NVDAV:N/AC:L/Au:S/C:P/I:N/A:N
6.5huntr.devCVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
6.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/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.

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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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-639Authorization Bypass Through User-Controlled Key
CWE-284Improper Access Control
T1213Data from Information Repositories

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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