CVE-2021-3963Public exploitNetwork attack vector

Data modification via tokenless state-changing requests

Published Nov 19, 2021 · Updated Aug 3, 2024

CSRF in Kimai before 1.16.2 allows remote attackers to alter or delete data by inducing authenticated users to send crafted requests. Customer and project comment pin/delete handlers and the invoice-template delete handler accept state-changing requests without CSRF tokens. Exploitation requires user interaction and an authenticated session with permission for the targeted operation, limiting effects to the victim's privileges.

CVSS severity4.3
Medium
EPSS probability0.40%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

CSRF in Kimai before 1.16.2 allows remote attackers to alter or delete data by inducing authenticated users to send crafted requests. Customer and project comment pin/delete handlers and the invoice-template delete handler accept state-changing requests without CSRF tokens. Exploitation requires user interaction and an authenticated session with permission for the targeted operation, limiting effects to the victim's privileges.

The record

CVE
CVE-2021-3963
Published
Nov 19, 2021
Updated
Aug 3, 2024
Vendor
Kevin Papst
Product
Kimai
Classifications
CWE-352
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 19, 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 privilegesunauthenticated

What is affected?

Kevin Papst · Kimaiversion=unspecified <1.16.2

Published CVSS scores

4.3NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
4.3huntr.devCVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/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.

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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-352Cross-Site Request Forgery (CSRF)

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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