CVE-2014-0099 Improper Neutralization of CRLF Sequences in HTTP Headers in Apache Tomcat

What is CVE-2014-0099?

CVE-2014-0099 is a medium-severity vulnerability in Apache Tomcat, published on 31 May 2014. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

Integer overflow in java/org/apache/tomcat/util/buf/Ascii.java in Apache Tomcat before 6.0.40, 7.x before 7.0.53, and 8.x before 8.0.4, when operated behind a reverse proxy, allows remote attackers to conduct HTTP request smuggling attacks via a crafted Content-Length HTTP header.

Weakness: CWE-189

Which versions are affected by CVE-2014-0099?

12 open source packages ship an affected version, including org.apache.tomcat:tomcat and org.apache.tomcat:tomcat-util. It affects 1 product.

Products include Apache Tomcat.

How do I fix CVE-2014-0099?

Upgrade org.apache.tomcat:tomcat to a fixed version for your release line: 6.0.40, 7.0.54 or 8.0.6.

Is CVE-2014-0099 being exploited?

There is no known exploitation of CVE-2014-0099 in the wild and no public exploit code.

Other vulnerabilities in Apache Tomcat

• CVE-2025-24813 Apache Tomcat Path Equivalence Exploited Critical 10.0
• CVE-2016-8735 Apache Tomcat Remote Code Execution Exploited Critical 9.8
• CVE-2017-12617 Apache Tomcat Remote Code Execution Exploited High 8.1
• CVE-2017-12615 Apache Tomcat on Windows Remote Code Execution Exploited High 8.1
• CVE-2026-34486 Apache Tomcat Missing Encryption of Sensitive Data Exploited High 7.5

All Apache Tomcat vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-xh5x-j8jf-pcpx, UBUNTU-CVE-2014-0099.