CVE-2017-2670: Vulnerability in io.undertow:undertow-core
Summary
CVE-2017-2670: Moderate severity vulnerability that affects io.undertow:undertow-core. Affects io.undertow:undertow-core versions < 1.3.28. Fixed in 1.3.28. How to fix ↓
Also tracked for
- undertow · Debian:13
The same CVE-2017-2670 is tracked separately for each ecosystem and vendor. Its fix information is the same; the package and affected versions differ.
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Background
io.undertow:undertow-core is a Maven package that provides core functionality for the Undertow web server. Undertow is a lightweight and high-performance web server written in Java. It is designed to be flexible and efficient, making it suitable for a wide range of applications. However, a vulnerability has been discovered in versions prior to 1.3.28 that can lead to a denial-of-service (DoS) attack.
Vulnerability Detail
The vulnerability, identified as CVE-2017-2670, occurs when the Websocket server in Undertow receives a non-clean TCP close. This triggers an infinite loop on every IO thread, resulting in a DoS condition. An attacker can exploit this vulnerability by sending specially crafted requests to the affected server, causing it to become unresponsive and potentially impacting the availability of the entire application.
How To Fix
Latest published version: 2.4.4.Final as of 23 Oct 2026
Upgrading to it may include breaking changes; the version below is the minimum fixed release for this vulnerability.
If you need the minimum change
1.3.28
This is the first release that contains the fix.
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Workaround
There is no known workaround for this vulnerability. It is essential to apply the recommended fix by upgrading to the patched version of io.undertow:undertow-core.
Conclusion
The vulnerability in io.undertow:undertow-core prior to version 1.3.28 can lead to a denial-of-service (DoS) attack. It is recommended to upgrade to the latest version to fix this vulnerability and ensure the security and availability of your application. For further support on vulnerability remediation, you can contact DevNack.com.
See every vulnerability recorded for io.undertow:undertow-core →
FAQ
This vulnerability can lead to a denial-of-service (DoS) attack, potentially causing the affected server to become unresponsive and impacting the availability of the entire application.
You can use Vulert's playground (https://vulert.com/scanner) to check if your application is affected by this vulnerability. Simply upload your pom.xml file, and Vulert will analyze it in real-time and alert you if any open-source vulnerabilities, including this one, are found.
While specific exploits for this vulnerability have not been disclosed, it is important to apply the recommended fix promptly to prevent potential attacks.
Yes, this vulnerability can be exploited remotely by sending specially crafted requests to the affected server.
There is no evidence of active exploitation of this vulnerability at the time of this advisory. However, it is crucial to apply the recommended fix to mitigate the risk.
References
Related vulnerabilities
Recent vulnerabilities recorded for io.undertow:undertow-core.
