Improper Authorization in Undertoe

Exploitation

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

CVSS

8.6 · CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L

EPSS

• CVE-2020-1745: 4.96% estimated exploitation activity in the next 30 days; percentile 92.19 (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.

A file inclusion vulnerability was found in the AJP connector enabled with a default AJP configuration port of 8009 in Undertow version 2.0.29.Final and before and was fixed in 2.0.30.Final. A remote, unauthenticated attacker could exploit this vulnerability to read web application files from a vulnerable server. In instances where the vulnerable server allows file uploads, an attacker could upload malicious JavaServer Pages (JSP) code within a variety of file types and trigger this vulnerability to gain remote code execution.

Published by the source

24 May 2022, 17:16 UTC

Last modified by the source

27 Jan 2023, 05:02 UTC

Source last checked

26 Oct 2026, 16:00 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-gv2w-88hx-8m9r

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# Patch Next advisory brief: CVE-2020-1745

Advisory: Improper Authorization in Undertoe
IDs: CVE-2020-1745, GHSA-gv2w-88hx-8m9r
Record: https://patchnext.com/advisories/cve-2020-1745 (revision 1, source checked 26 Oct 2026, 16:00 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.6)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: io.undertow:undertow-core 2.0.30. A vendor fix does not mean a deployment is fixed.

## Affected components
- Maven io.undertow:undertow-core: affected <= 2.0.29; fixed in 2.0.30

## Suggested inspection (read-only)
- Maven io.undertow:undertow-core: 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 io.undertow:undertow-core.
- 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-gv2w-88hx-8m9r (GitHub-reviewed advisory GHSA-gv2w-88hx-8m9r lists affected ranges: Maven io.undertow:undertow-core >=0 <=2.0.29)

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