#VU55423 Inconsistent interpretation of HTTP requests in Apache Tomcat

Published: 2021-07-29

Vulnerability identifier: #VU55423

Vulnerability risk: Medium


CVE-ID: CVE-2021-33037


Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Apache Tomcat
Server applications / Web servers

Vendor: Apache Foundation


The vulnerability allows a remote attacker to preform HTTP request smuggling attacks.

The vulnerability exists due to improper validation of HTTP requests, related to processing of transfer encoding headers.  A remote attacker can send a specially crafted HTTP request to the server and smuggle arbitrary HTTP headers.

Successful exploitation of vulnerability may allow an attacker to poison HTTP cache and perform phishing attacks.

Install updates from vendor's website.

Vulnerable software versions

Apache Tomcat: 10.0.0 - 10.0.6, 9.0.0 - 9.0.46, 8.5.0 - 8.5.66


External links

Q & A

Can this vulnerability be exploited remotely?

Is there known malware, which exploits this vulnerability?

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