Apache Tomcat 4.1.0 through 4.1.39, 5.5.0 through 5.5.27, and 6.0.0 through 6.0.18, when the Java AJP connector and mod_jk load balancing are used, allows remote attackers to cause a denial of service (application outage) via a crafted request with invalid headers, related to temporary blocking of connectors that have encountered errors, as demonstrated by an error involving a malformed HTTP Host header.

When using a Spring AOP functionality to secure Struts actions it is possible to perform a DoS attack. Solution is to upgrade to Apache Struts version 2.5.12 or 2.3.33.

When under stress, closing many connections, the HTTP/2 handling code in Apache httpd 2.4.26 would sometimes access memory after it has been freed, resulting in potentially erratic behaviour.

In Apache SpamAssassin before 3.4.3, a message can be crafted in a way to use excessive resources. Upgrading to SA 3.4.3 as soon as possible is the recommended fix but details will not be shared publicly.

While investigating UBSAN errors in https://github.com/apache/arrow/pull/5365 it was discovered Apache Arrow versions 0.12.0 to 0.14.1, left memory Array data uninitialized when reading RLE null data from parquet. This affected the C++, Python, Ruby and R implementations. The uninitialized memory could potentially be shared if are transmitted over the wire (for instance with Flight) or persisted in the streaming IPC and file formats.

The (1) mod_cache and (2) mod_dav modules in the Apache HTTP Server 2.2.x before 2.2.16 allow remote attackers to cause a denial of service (process crash) via a request that lacks a path.

The XML parser in Xerces-C++ 2.5.0 allows remote attackers to cause a denial of service (CPU consumption) via XML attributes in a crafted XML document.

mod_ssl in Apache 2.0.50 and earlier allows remote attackers to cause a denial of service (CPU consumption) by aborting an SSL connection in a way that causes an Apache child process to enter an infinite loop.

Unknown vulnerability in mod_python 2.7.9 allows remote attackers to cause a denial of service (httpd crash) via a certain query string, a variant of CAN-2003-0973.

mod_dav in Apache before 2.0.42 does not properly handle versioning hooks, which may allow remote attackers to kill a child process via a null dereference and cause a denial of service (CPU consumption) in a preforked multi-processing module.

A carefully crafted invalid TLS handshake can cause Apache Traffic Server (ATS) to segfault. This affects version 6.2.2. To resolve this issue users running 6.2.2 should upgrade to 6.2.3 or later versions.

The (1) mod_dav_svn and (2) svnserve servers in Subversion 1.6.0 through 1.7.19 and 1.8.0 through 1.8.11 allow remote attackers to cause a denial of service (assertion failure and abort) via crafted parameter combinations related to dynamically evaluated revision numbers.

The lua_websocket_read function in lua_request.c in the mod_lua module in the Apache HTTP Server through 2.4.12 allows remote attackers to cause a denial of service (child-process crash) by sending a crafted WebSocket Ping frame after a Lua script has called the wsupgrade function.

In Apache ORC 1.0.0 to 1.4.3 a malformed ORC file can trigger an endlessly recursive function call in the C++ or Java parser. The impact of this bug is most likely denial-of-service against software that uses the ORC file parser. With the C++ parser, the stack overflow might possibly corrupt the stack.

qpidd in Apache Qpid 0.30 and earlier allows remote attackers to cause a denial of service (daemon crash) via a crafted protocol sequence set. NOTE: this vulnerability exists because of an incomplete fix for CVE-2015-0203.

The prefork MPM in Apache 2 before 2.0.47 does not properly handle certain errors from accept, which could lead to a denial of service.

The mod_dav_svn Apache HTTPD server module in Apache Subversion 1.7.x before 1.7.19 and 1.8.x before 1.8.11 allows remote attackers to cause a denial of service (NULL pointer dereference and crash) via a request for a URI that triggers a lookup for a virtual transaction name that does not exist.

The mod_dav_svn Apache HTTPD server module in Apache Subversion 1.x before 1.7.19 and 1.8.x before 1.8.11 allows remote attackers to cause a denial of service (NULL pointer dereference and server crash) via a REPORT request for a resource that does not exist.

The processControlCommand function in broker/TransportConnection.java in Apache ActiveMQ before 5.11.0 allows remote attackers to cause a denial of service (shutdown) via a shutdown command.

The cache_merge_headers_out function in modules/cache/cache_util.c in the mod_cache module in the Apache HTTP Server before 2.4.11 allows remote attackers to cause a denial of service (NULL pointer dereference and application crash) via an empty HTTP Content-Type header.

Memory leak in the winnt_accept function in server/mpm/winnt/child.c in the WinNT MPM in the Apache HTTP Server 2.4.x before 2.4.10 on Windows, when the default AcceptFilter is enabled, allows remote attackers to cause a denial of service (memory consumption) via crafted requests.

The handle_headers function in mod_proxy_fcgi.c in the mod_proxy_fcgi module in the Apache HTTP Server 2.4.10 allows remote FastCGI servers to cause a denial of service (buffer over-read and daemon crash) via long response headers.

The SamlHeaderInHandler in Apache CXF before 2.6.11, 2.7.x before 2.7.8, and 3.0.x before 3.0.1 allows remote attackers to cause a denial of service (infinite loop) via a crafted SAML token in the authorization header of a request to a JAX-RS service.

Apache CouchDB 1.5.0 and earlier allows remote attackers to cause a denial of service (CPU and memory consumption) via the count parameter to /_uuids.

The log_cookie function in mod_log_config.c in the mod_log_config module in the Apache HTTP Server before 2.4.8 allows remote attackers to cause a denial of service (segmentation fault and daemon crash) via a crafted cookie that is not properly handled during truncation.

The mod_cgid module in the Apache HTTP Server before 2.4.10 does not have a timeout mechanism, which allows remote attackers to cause a denial of service (process hang) via a request to a CGI script that does not read from its stdin file descriptor.

qpid-cpp: ACL policies only loaded if the acl-file option specified enabling DoS by consuming all available file descriptors

java/org/apache/coyote/ajp/AbstractAjpProcessor.java in Apache Tomcat 8.x before 8.0.4 allows remote attackers to cause a denial of service (thread consumption) by using a "Content-Length: 0" AJP request to trigger a hang in request processing.

Apache Traffic Server before 5.1.2 allows remote attackers to cause a denial of service via unspecified vectors, related to internal buffer sizing.

Integer overflow in the parseChunkHeader function in java/org/apache/coyote/http11/filters/ChunkedInputFilter.java in Apache Tomcat before 6.0.40, 7.x before 7.0.53, and 8.x before 8.0.4 allows remote attackers to cause a denial of service (resource consumption) via a malformed chunk size in chunked transfer coding of a request during the streaming of data.

When a client request to a cluster node was replicated to other nodes in the cluster for verification, the Content-Length was forwarded. On a DELETE request, the body was ignored, but if the initial request had a Content-Length value other than 0, the receiving nodes would wait for the body and eventually timeout. Mitigation: The fix to check DELETE requests and overwrite non-zero Content-Length header values was applied on the Apache NiFi 1.8.0 release. Users running a prior 1.x release should upgrade to the appropriate release.

The dav_xml_get_cdata function in main/util.c in the mod_dav module in the Apache HTTP Server before 2.4.8 does not properly remove whitespace characters from CDATA sections, which allows remote attackers to cause a denial of service (daemon crash) via a crafted DAV WRITE request.

The Apache Struts REST Plugin is using XStream library which is vulnerable and allow perform a DoS attack when using a malicious request with specially crafted XML payload. Upgrade to the Apache Struts version 2.5.16 and switch to an optional Jackson XML handler as described here http://struts.apache.org/plugins/rest/#custom-contenttypehandlers. Another option is to implement a custom XML handler based on the Jackson XML handler from the Apache Struts 2.5.16.

When parsing a JSON payload with deeply nested JSON structures, the parser in Apache Mesos versions pre-1.4.x, 1.4.0 to 1.4.2, 1.5.0 to 1.5.1, 1.6.0 to 1.6.1, and 1.7.0 might overflow the stack due to unbounded recursion. A malicious actor can therefore cause a denial of service of Mesos masters rendering the Mesos-controlled cluster inoperable.

Subversion's mod_dav_svn Apache HTTPD module versions 1.11.0 and 1.10.0 to 1.10.3 will crash after dereferencing an uninitialized pointer if the client omits the root path in a recursive directory listing operation.

In Apache Tika 0.1 to 1.18, the XML parsers were not configured to limit entity expansion. They were therefore vulnerable to an entity expansion vulnerability which can lead to a denial of service attack.

The ap_proxy_http_process_response function in mod_proxy_http.c in the mod_proxy module in the Apache HTTP Server 2.0.63 and 2.2.8 does not limit the number of forwarded interim responses, which allows remote HTTP servers to cause a denial of service (memory consumption) via a large number of interim responses.

The date handling code in modules/proxy/proxy_util.c (mod_proxy) in Apache 2.3.0, when using a threaded MPM, allows remote origin servers to cause a denial of service (caching forward proxy process crash) via crafted date headers that trigger a buffer over-read.

In Apache Struts 2.3.7 through 2.3.33 and 2.5 through 2.5.12, if an application allows entering a URL in a form field and built-in URLValidator is used, it is possible to prepare a special URL which will be used to overload server process when performing validation of the URL. NOTE: this vulnerability exists because of an incomplete fix for S2-047 / CVE-2017-7672.

The Apache HTTP Server 1.x and 2.x allows remote attackers to cause a denial of service (daemon outage) via partial HTTP requests, as demonstrated by Slowloris, related to the lack of the mod_reqtimeout module in versions before 2.2.15.

When handling a decoding failure for a malformed URL path of an HTTP request, libprocess in Apache Mesos before 1.1.3, 1.2.x before 1.2.2, 1.3.x before 1.3.1, and 1.4.0-dev might crash because the code accidentally calls inappropriate function. A malicious actor can therefore cause a denial of service of Mesos masters rendering the Mesos-controlled cluster inoperable.

Apache Traffic Server 6.0.0 to 6.2.3, 7.0.0 to 7.1.10, and 8.0.0 to 8.0.7 is vulnerable to certain types of HTTP/2 HEADERS frames that can cause the server to allocate a large amount of memory and spin the thread.

Apache HTTP Server versions 2.4.20 to 2.4.43. A specially crafted value for the 'Cache-Digest' header in a HTTP/2 request would result in a crash when the server actually tries to HTTP/2 PUSH a resource afterwards. Configuring the HTTP/2 feature via "H2Push off" will mitigate this vulnerability for unpatched servers.

PerlRun.pm in Apache mod_perl before 1.30, and RegistryCooker.pm in mod_perl 2.x, does not properly escape PATH_INFO before use in a regular expression, which allows remote attackers to cause a denial of service (resource consumption) via a crafted URI.

Integer overflow in the qpid::framing::Buffer::checkAvailable function in Apache Qpid 0.20 and earlier allows remote attackers to cause a denial of service (crash) via a crafted message, which triggers an out-of-bounds read.

java/org/apache/coyote/http11/InternalNioInputBuffer.java in the HTTP NIO connector in Apache Tomcat 6.x before 6.0.36 and 7.x before 7.0.28 does not properly restrict the request-header size, which allows remote attackers to cause a denial of service (memory consumption) via a large amount of header data.

Apache Qpid 0.17 and earlier does not properly restrict incoming client connections, which allows remote attackers to cause a denial of service (file descriptor consumption) via a large number of incomplete connections.

Apache Tomcat 5.5.x before 5.5.35, 6.x before 6.0.34, and 7.x before 7.0.23 uses an inefficient approach for handling parameters, which allows remote attackers to cause a denial of service (CPU consumption) via a request that contains many parameters and parameter values, a different vulnerability than CVE-2011-4858.

Attackers can use public NetTest web service of Apache OpenMeetings 4.0.0-5.0.0 to organize denial of service attack.