CVE-2017-7559

Severity: medium (CVSS 6.1 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.9% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2018-01-10 · updated 2026-06-17
Weakness: CWE-444

Description

In Undertow 2.x before 2.0.0.Alpha2, 1.4.x before 1.4.17.Final, and 1.3.x before 1.3.31.Final, it was found that the fix for CVE-2017-2666 was incomplete and invalid characters are still allowed in the query string and path parameters. This could be exploited, in conjunction with a proxy that also permitted the invalid characters but with a different interpretation, to inject data into the HTTP response. By manipulating the HTTP response the attacker could poison a web-cache, perform an XSS attack, or obtain sensitive information from requests other than their own.

Affected products

Red Hat undertow: from 1.3.0 before 1.3.31; from 1.4.0 before 1.4.17; 2.0.0-alpha1 — fixed in 1.3.31, 1.4.17

How to fix

Upgrade to a fixed version: Red Hat undertow 1.3.31, 1.4.17. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2017-7559 or the next vulnerability affects your stack