Apache Tomcat

The Tomcat init script in the tomcat7 package before 7.0.56-3+deb8u4 and tomcat8 package before 8.0.14-1+deb8u3 on Debian jessie and the tomcat6 and libtomcat6-java packages before 6.0.35-1ubuntu3.8 on Ubuntu 12.04 LTS, the tomcat7 and libtomcat7-java packages before 7.0.52-1ubuntu0.7 on Ubuntu 14.04 LTS, and tomcat8 and libtomcat8-java packages before 8.0.32-1ubuntu1.2 on Ubuntu 16.04 LTS allows local users with access to the tomcat account to gain root privileges via a symlink attack on the Catalina log file, as demonstrated by /var/log/tomcat7/catalina.out.

Tomcat 4.0 through 4.1.12, using mod_jk 1.2.1 module on Apache 1.3 through 1.3.27, allows remote attackers to cause a denial of service (desynchronized communications) via an HTTP GET request with a Transfer-Encoding chunked field with invalid values.

The AJP connector in Apache Tomcat 5.5.15 uses an incorrect length for chunks, which can cause a buffer over-read in the ajp_process_callback in mod_jk, which allows remote attackers to read portions of sensitive memory.

The Tomcat package on Red Hat Enterprise Linux (RHEL) 7, Fedora, CentOS, Oracle Linux, and possibly other Linux distributions uses weak permissions for /usr/lib/tmpfiles.d/tomcat.conf, which allows local users to gain root privileges by leveraging membership in the tomcat group.

The HTTP/1.1 connector in Apache Tomcat 4.1.15 through 4.1.40 does not reject NULL bytes in a URL when allowLinking is configured, which allows remote attackers to read JSP source files and obtain sensitive information.

User-writeable configuration file /usr/lib/tmpfiles.d/tomcat.conf allows for escalation of priviliges

The postinst script in the tomcat6 package before 6.0.45+dfsg-1~deb7u4 on Debian wheezy, before 6.0.35-1ubuntu3.9 on Ubuntu 12.04 LTS and on Ubuntu 14.04 LTS; the tomcat7 package before 7.0.28-4+deb7u8 on Debian wheezy, before 7.0.56-3+deb8u6 on Debian jessie, before 7.0.52-1ubuntu0.8 on Ubuntu 14.04 LTS, and on Ubuntu 12.04 LTS, 16.04 LTS, and 16.10; and the tomcat8 package before 8.0.14-1+deb8u5 on Debian jessie, before 8.0.32-1ubuntu1.3 on Ubuntu 16.04 LTS, before 8.0.37-1ubuntu0.1 on Ubuntu 16.10, and before 8.0.38-2ubuntu1 on Ubuntu 17.04 might allow local users with access to the tomcat account to obtain sensitive information or gain root privileges via a symlink attack on the Catalina localhost directory.

The postrm script in the tomcat6 package before 6.0.45+dfsg-1~deb7u3 on Debian wheezy, before 6.0.45+dfsg-1~deb8u1 on Debian jessie, before 6.0.35-1ubuntu3.9 on Ubuntu 12.04 LTS and on Ubuntu 14.04 LTS; the tomcat7 package before 7.0.28-4+deb7u7 on Debian wheezy, before 7.0.56-3+deb8u6 on Debian jessie, before 7.0.52-1ubuntu0.8 on Ubuntu 14.04 LTS, and on Ubuntu 12.04 LTS, 16.04 LTS, and 16.10; and the tomcat8 package before 8.0.14-1+deb8u5 on Debian jessie, before 8.0.32-1ubuntu1.3 on Ubuntu 16.04 LTS, before 8.0.37-1ubuntu0.1 on Ubuntu 16.10, and before 8.0.38-2ubuntu1 on Ubuntu 17.04 might allow local users with access to the tomcat account to gain root privileges via a setgid program in the Catalina directory, as demonstrated by /etc/tomcat8/Catalina/attack.

The Tomcat package on Red Hat Enterprise Linux (RHEL) 5 through 7, JBoss Web Server 3.0, and JBoss EWS 2 uses weak permissions for (1) /etc/sysconfig/tomcat and (2) /etc/tomcat/tomcat.conf, which allows local users to gain privileges by leveraging membership in the tomcat group.

The HTTP/2 protocol allows a denial of service (server resource consumption) because request cancellation can reset many streams quickly, as exploited in the wild in August through October 2023.

Apache Tomcat: Fix for CVE-2026-29146 allowed bypass of EncryptInterceptor

The payload length in a WebSocket frame was not correctly validated in Apache Tomcat 10.0.0-M1 to 10.0.0-M6, 9.0.0.M1 to 9.0.36, 8.5.0 to 8.5.56 and 7.0.27 to 7.0.104. Invalid payload lengths could trigger an infinite loop. Multiple requests with invalid payload lengths could lead to a denial of service.

MultipartStream.java in Apache Commons FileUpload before 1.3.1, as used in Apache Tomcat, JBoss Web, and other products, allows remote attackers to cause a denial of service (infinite loop and CPU consumption) via a crafted Content-Type header that bypasses a loop's intended exit conditions.

The Windows installer for Apache Tomcat 6.0.0 through 6.0.20, 5.5.0 through 5.5.28, and possibly earlier versions uses a blank default password for the administrative user, which allows remote attackers to gain privileges.

EncryptInterceptor does not provide complete protection on insecure networks

The fix for CVE-2019-0199 was incomplete and did not address HTTP/2 connection window exhaustion on write in Apache Tomcat versions 9.0.0.M1 to 9.0.19 and 8.5.0 to 8.5.40 . By not sending WINDOW_UPDATE messages for the connection window (stream 0) clients were able to cause server-side threads to block eventually leading to thread exhaustion and a DoS.

The HTTP/2 implementation in Apache Tomcat 9.0.0.M1 to 9.0.14 and 8.5.0 to 8.5.37 accepted streams with excessive numbers of SETTINGS frames and also permitted clients to keep streams open without reading/writing request/response data. By keeping streams open for requests that utilised the Servlet API's blocking I/O, clients were able to cause server-side threads to block eventually leading to thread exhaustion and a DoS.

When using a VirtualDirContext with Apache Tomcat 7.0.0 to 7.0.80 it was possible to bypass security constraints and/or view the source code of JSPs for resources served by the VirtualDirContext using a specially crafted request.

Apache Tomcat: Directory traversal via rewrite with possible RCE if PUT is enabled

An h2c direct connection to Apache Tomcat 10.0.0-M1 to 10.0.0-M6, 9.0.0.M5 to 9.0.36 and 8.5.1 to 8.5.56 did not release the HTTP/1.1 processor after the upgrade to HTTP/2. If a sufficient number of such requests were made, an OutOfMemoryException could occur leading to a denial of service.

Apache Tomcat: DoS via malformed HTTP/2 PRIORITY_UPDATE frame

Apache Tomcat: Fix for CVE-2023-24998 is incomplete

Apache Tomcat: FileUpload large number of parts with headers DoS

A specially crafted sequence of HTTP/2 requests sent to Apache Tomcat 10.0.0-M1 to 10.0.0-M5, 9.0.0.M1 to 9.0.35 and 8.5.0 to 8.5.55 could trigger high CPU usage for several seconds. If a sufficient number of such requests were made on concurrent HTTP/2 connections, the server could become unresponsive.

Apache Tomcat: Request header mix-up between HTTP/2 streams

Apache Tomcat: HTTP/2 header handling DoS

The host name verification when using TLS with the WebSocket client was missing. It is now enabled by default. Versions Affected: Apache Tomcat 9.0.0.M1 to 9.0.9, 8.5.0 to 8.5.31, 8.0.0.RC1 to 8.0.52, and 7.0.35 to 7.0.88.

An improper handing of overflow in the UTF-8 decoder with supplementary characters can lead to an infinite loop in the decoder causing a Denial of Service. Versions Affected: Apache Tomcat 9.0.0.M9 to 9.0.7, 8.5.0 to 8.5.30, 8.0.0.RC1 to 8.0.51, and 7.0.28 to 7.0.86.

Apache Tomcat h2c request mix-up

A bug in the handling of the pipelined requests in Apache Tomcat 9.0.0.M1 to 9.0.0.M18, 8.5.0 to 8.5.12, 8.0.0.RC1 to 8.0.42, 7.0.0 to 7.0.76, and 6.0.0 to 6.0.52, when send file was used, results in the pipelined request being lost when send file processing of the previous request completed. This could result in responses appearing to be sent for the wrong request. For example, a user agent that sent requests A, B and C could see the correct response for request A, the response for request C for request B and no response for request C.

The error page mechanism of the Java Servlet Specification requires that, when an error occurs and an error page is configured for the error that occurred, the original request and response are forwarded to the error page. This means that the request is presented to the error page with the original HTTP method. If the error page is a static file, expected behaviour is to serve content of the file as if processing a GET request, regardless of the actual HTTP method. The Default Servlet in Apache Tomcat 9.0.0.M1 to 9.0.0.M20, 8.5.0 to 8.5.14, 8.0.0.RC1 to 8.0.43 and 7.0.0 to 7.0.77 did not do this. Depending on the original request this could lead to unexpected and undesirable results for static error pages including, if the DefaultServlet is configured to permit writes, the replacement or removal of the custom error page. Notes for other user provided error pages: (1) Unless explicitly coded otherwise, JSPs ignore the HTTP method. JSPs used as error pages must must ensure that they handle any error dispatch as a GET request, regardless of the actual method. (2) By default, the response generated by a Servlet does depend on the HTTP method. Custom Servlets used as error pages must ensure that they handle any error dispatch as a GET request, regardless of the actual method.

A bug in the error handling of the send file code for the NIO HTTP connector in Apache Tomcat 9.0.0.M1 to 9.0.0.M13, 8.5.0 to 8.5.8, 8.0.0.RC1 to 8.0.39, 7.0.0 to 7.0.73 and 6.0.16 to 6.0.48 resulted in the current Processor object being added to the Processor cache multiple times. This in turn meant that the same Processor could be used for concurrent requests. Sharing a Processor can result in information leakage between requests including, not not limited to, session ID and the response body. The bug was first noticed in 8.5.x onwards where it appears the refactoring of the Connector code for 8.5.x onwards made it more likely that the bug was observed. Initially it was thought that the 8.5.x refactoring introduced the bug but further investigation has shown that the bug is present in all currently supported Tomcat versions.

Certain AJP protocol connector implementations in Apache Tomcat 7.0.0 through 7.0.20, 6.0.0 through 6.0.33, 5.5.0 through 5.5.33, and possibly other versions allow remote attackers to spoof AJP requests, bypass authentication, and obtain sensitive information by causing the connector to interpret a request body as a new request.

Cross-site scripting vulnerability in Apache Tomcat 4.0.3 allows remote attackers to execute script as other web users via script in a URL with the /servlet/ mapping, which does not filter the script when an exception is thrown by the servlet.

DoS via memory leak with WebSocket connections

When using FORM authentication with Apache Tomcat 9.0.0.M1 to 9.0.29, 8.5.0 to 8.5.49 and 7.0.0 to 7.0.98 there was a narrow window where an attacker could perform a session fixation attack. The window was considered too narrow for an exploit to be practical but, erring on the side of caution, this issue has been treated as a security vulnerability.

The HTTP/2 implementation in Apache Tomcat 9.0.0.M1 to 9.0.0.M21 and 8.5.0 to 8.5.15 bypassed a number of security checks that prevented directory traversal attacks. It was therefore possible to bypass security constraints using a specially crafted URL.

Apache Tomcat: EncryptInterceptor vulnerable to padding oracle attack by default

A malicious web application running on Apache Tomcat 9.0.0.M1 to 9.0.0.M9, 8.5.0 to 8.5.4, 8.0.0.RC1 to 8.0.36, 7.0.0 to 7.0.70 and 6.0.0 to 6.0.45 was able to bypass a configured SecurityManager via manipulation of the configuration parameters for the JSP Servlet.

In Apache Tomcat 9.0.0.M1 to 9.0.0.M18 and 8.5.0 to 8.5.12, the handling of an HTTP/2 GOAWAY frame for a connection did not close streams associated with that connection that were currently waiting for a WINDOW_UPDATE before allowing the application to write more data. These waiting streams each consumed a thread. A malicious client could therefore construct a series of HTTP/2 requests that would consume all available processing threads.