CVE-2018-14642 — undertow-core
MEDIUMCVE-2018-14642 is a medium-severity (CVSS 5.3) Information Exposure vulnerability in io.undertow:undertow-core. A fix is available for io.undertow:undertow-core — see the affected versions and patch details below.
Exposure of Sensitive Information to an Unauthorized Actor in Undertow
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
An information leak vulnerability was found in Undertow. If all headers are not written out in the first write() call then the code that handles flushing the buffer will always write out the full contents of the writevBuffer buffer, which may contain data from previous requests.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | io.undertow:undertow-core | all versions | 2.0.19.FINALio.undertow:undertow-core:2.0.19.FINAL |
Affected Products
jboss enterprise application platformredhatundertowredhatDetection & 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 2.0.19.FINAL or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2018-14642 is resolved across your whole dependency graph.
Workarounds
Assume what was exposed is already known: rotate any credential, token or key that the affected component could return, restrict the endpoint to callers that genuinely need it, and strip sensitive fields from responses and error output at the boundary rather than relying on the client not to read them.
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.
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat JBoss EAP 7.2 | undertow | RHSA-2019:1106 |
| Red Hat JBoss Enterprise Application Platform 7.1 for RHEL 6 | eap7-activemq-artemis-0:1.5.5.015-1.redhat_00001.1.ep7.el6 | RHSA-2019:0364 |
| Red Hat JBoss Enterprise Application Platform 7.1 for RHEL 7 | eap7-activemq-artemis-0:1.5.5.015-1.redhat_00001.1.ep7.el7 | RHSA-2019:0365 |
| Red Hat JBoss Enterprise Application Platform 7.2 for RHEL 6 | eap7-activemq-artemis-0:2.6.3-5.redhat_00020.1.el6eap | RHSA-2019:1107 |
| Red Hat JBoss Enterprise Application Platform 7.2 for RHEL 7 | eap7-activemq-artemis-0:2.6.3-5.redhat_00020.1.el7eap | RHSA-2019:1108 |
| Red Hat Single Sign-On 7.2.6 zip | undertow | RHSA-2019:0380 |
| Red Hat Single Sign-On 7.3.1 zip | see advisory | RHSA-2019:1140 |
| Red Hat Virtualization 4 for Red Hat Enterprise Linux 7 | rhvm-appliance-0:4.3-20190502.0.el7 | RHEA-2019:1119 |
Frequently Asked Questions
Is CVE-2018-14642 in your dependencies?
Find it across Maven, including transitive dependencies.