CVE-2020-1745 — undertow-core
CRITICALCVE-2020-1745 is a critical-severity (CVSS 9.8) CWE-285 vulnerability in io.undertow:undertow-core. A fix is available for io.undertow:undertow-core — see the affected versions and patch details below.
Improper Authorization in Undertoe
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
io.undertow:undertow-coreReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
Description
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | io.undertow:undertow-core | all versions | 2.0.30io.undertow:undertow-core:2.0.30 |
Affected Products
undertowredhatDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for io.undertow:undertow-core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update io.undertow:undertow-core to 2.0.30 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-1745 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
Please refer to the Red Hat knowledgebase article: https://access.redhat.com/solutions/4851251 and CVE page https://access.redhat.com/security/cve/cve-2020-1938
Please refer to the Red Hat knowledgebase article: https://access.redhat.com/solutions/4851251Source: Red Hat security advisory for CVE-2020-1745 (CC BY 4.0)
| Product | Fixed in | Advisory |
|---|---|---|
| EAP-CD 19 Tech Preview | undertow | RHSA-2020:2333 |
| Red Hat Data Grid 7.3.7 | undertow | RHSA-2020:3779 |
| Red Hat Fuse 7.7.0 | undertow | RHSA-2020:3192 |
| Red Hat JBoss EAP 7 | undertow-core | RHSA-2020:2515 |
| Red Hat JBoss EAP 7.2 | undertow-core | RHSA-2020:0812 |
| Red Hat JBoss EAP 7.2 | undertow-core | RHSA-2020:2061 |
| Red Hat JBoss Enterprise Application Platform 7 | undertow-core | RHSA-2020:0961 |
| Red Hat JBoss Enterprise Application Platform 7.1 EUS for RHEL 7 | eap7-undertow-0:1.4.18-12.SP12_redhat_00001.1.ep7.el7 | RHSA-2024:5856 |
Frequently Asked Questions
Is CVE-2020-1745 in your dependencies?
Find it across Maven, including transitive dependencies.