Kimai (Authenticated) SSTI to RCE by Uploading a Malicious Twig File

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

7.2 · CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

EPSS

• CVE-2023-46245: 1.80% estimated exploitation activity in the next 30 days; percentile 78.51 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Description The laters version of Kimai is found to be vulnerable to a critical Server-Side Template Injection (SSTI) which can be escalated to Remote Code Execution (RCE). The vulnerability arises when a malicious user uploads a specially crafted Twig file, exploiting the software's PDF and HTML rendering functionalities. Snippet of Vulnerable Code: The vulnerability is triggered when the software attempts to render invoices, allowing the attacker to execute arbitrary code on the server. In below, you can find the docker-compose file was used for this testing: Steps to Reproduce (Manually): 1- Upload a malicious Twig file to the server containing the following payload 2- Trigger the SSTI vulnerability by downloading the invoices. 3- The malicious code gets executed, leading to RCE. 4- /tmp/pwned file will be created on the target system I've also attached an automated script to ease up the process of reproducing:

Proof of Concept which can be executed as such: this will download…

Published by the source

30 Oct 2023, 15:40 UTC

Last modified by the source

12 Jan 2024, 16:37 UTC

Source last checked

26 Oct 2026, 14:14 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-fjhg-96cp-6fcw

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# Patch Next advisory brief: CVE-2023-46245

Advisory: Kimai (Authenticated) SSTI to RCE by Uploading a Malicious Twig File
IDs: CVE-2023-46245, GHSA-fjhg-96cp-6fcw
Record: https://patchnext.com/advisories/cve-2023-46245 (revision 1, source checked 26 Oct 2026, 14:14 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.2)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: kimai/kimai 2.1.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist kimai/kimai: affected < 2.1.0; fixed in 2.1.0

## Suggested inspection (read-only)
- Packagist kimai/kimai: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on kimai/kimai.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-fjhg-96cp-6fcw (GitHub-reviewed advisory GHSA-fjhg-96cp-6fcw lists affected ranges: Packagist kimai/kimai >=0 <2.1.0)

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