A path traversal vulnerability was found in Undertow. This issue may allow a remote attacker to append a specially-crafted sequence to an HTTP request for an application deployed to JBoss EAP, which may permit access to privileged or restricted files and directories.

A flaw was found in Undertow. A regression in the fix for CVE-2020-10687 was found. HTTP request smuggling related to CVE-2017-2666 is possible against HTTP/1.x and HTTP/2 due to permitting invalid characters in an HTTP request. This flaw allows an attacker to poison a web-cache, perform an XSS attack, or obtain sensitive information from request other than their own. The highest threat from this vulnerability is to data confidentiality and integrity.

A flaw was reported in WildFly 12.0.0.CR1 web server is vulnerable to the injection of arbitrary HTTP Header due to insufficient sanitisation and validation of user UTF-8 encoded input before it is used as part of an HTTP header value.

Although there is a protection against CRLF injection by detecting the presence of a NewLine character (0x0a), it can be bypassed using characters encoded in UTF-8 as the page will try to convert them back to the original Unicode form and extract the last byte.

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.

It was discovered in Undertow that the code that parsed the HTTP request line permitted invalid characters. 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.

A flaw was discovered in all versions of Undertow before Undertow 2.2.0.Final, where HTTP request smuggling related to CVE-2017-2666 is possible against HTTP/1.x and HTTP/2 due to permitting invalid characters in an HTTP request. This flaw allows an attacker to poison a web-cache, perform an XSS attack, or obtain sensitive information from request other than their own.

It was discovered that when using Digest authentication, the server does not ensure that the value of the URI in the authorization header matches the URI in the HTTP request line. This allows the attacker to execute a MITM attack and access the desired content on the server.

A flaw was found in Undertow in versions before 2.1.1.Final, regarding the processing of invalid HTTP requests with large chunk sizes. This flaw allows an attacker to take advantage of HTTP request smuggling.

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.

It was found that URLResource.getLastModified() in Undertow closes the file descriptors only when they are finalized which can cause file descriptors to exhaust. This leads to a file handler leak.