If was found that the NetTest web service can be used to overload the bandwidth of a Apache OpenMeetings server. This issue was addressed in Apache OpenMeetings 6.0.0

The ap_proxy_ajp_request function in mod_proxy_ajp.c in mod_proxy_ajp in the Apache HTTP Server 2.2.x before 2.2.15 does not properly handle certain situations in which a client sends no request body, which allows remote attackers to cause a denial of service (backend server outage) via a crafted request, related to use of a 500 error code instead of the appropriate 400 error code.

The Artofdefence Hyperguard Web Application Firewall (WAF) module before 2.5.5-11635, 3.0 before 3.0.3-11636, and 3.1 before 3.1.1-11637, a module for the Apache HTTP Server, allows remote attackers to cause a denial of service (memory consumption) via an HTTP request with a large Content-Length value but no POST data.

Apache HTTP Server versions 2.4.0 to 2.4.46 A specially crafted Cookie header handled by mod_session can cause a NULL pointer dereference and crash, leading to a possible Denial Of Service

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 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 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.

The expat XML parser in the apr_xml_* interface in xml/apr_xml.c in Apache APR-util before 1.3.7, as used in the mod_dav and mod_dav_svn modules in the Apache HTTP Server, allows remote attackers to cause a denial of service (memory consumption) via a crafted XML document containing a large number of nested entity references, as demonstrated by a PROPFIND request, a similar issue to CVE-2003-1564.

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 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.

Vulnerability in the Java SE, Java SE Embedded, JRockit component of Oracle Java SE (subcomponent: JAXP). Supported versions that are affected are Java SE: 7u171, 8u162 and 10; Java SE Embedded: 8u161; JRockit: R28.3.17. Easily exploitable vulnerability allows unauthenticated attacker with network access via multiple protocols to compromise Java SE, Java SE Embedded, JRockit. Successful attacks of this vulnerability can result in unauthorized ability to cause a partial denial of service (partial DOS) of Java SE, Java SE Embedded, JRockit. Note: Applies to client and server deployment of Java. This vulnerability can be exploited through sandboxed Java Web Start applications and sandboxed Java applets. It can also be exploited by supplying data to APIs in the specified Component without using sandboxed Java Web Start applications or sandboxed Java applets, such as through a web service. CVSS 3.0 Base Score 5.3 (Availability impacts). CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L).

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.

Certain input files could make the code hang when Apache Sanselan 0.97-incubator was used to parse them, which could be used in a DoS attack. Note that Apache Sanselan (incubating) was renamed to Apache Commons Imaging.

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.

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.

Certain input files could make the code to enter into an infinite loop when Apache Sanselan 0.97-incubator was used to parse them, which could be used in a DoS attack. Note that Apache Sanselan (incubating) was renamed to Apache Commons Imaging.

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.

A specially crafted HTTP request header could have crashed the Apache HTTP Server prior to version 2.4.30 due to an out of bound read while preparing data to be cached in shared memory. It could be used as a Denial of Service attack against users of mod_cache_socache. The vulnerability is considered as low risk since mod_cache_socache is not widely used, mod_cache_disk is not concerned by this vulnerability.

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 parsing a malformed JSON payload, libprocess in Apache Mesos versions 1.4.0 to 1.5.0 might crash due to an uncaught exception. Parsing chunked HTTP requests with trailers can lead to a libprocess crash too because of the mistakenly planted assertion. A malicious actor can therefore cause a denial of service of Mesos masters rendering the Mesos-controlled cluster inoperable.

Adding method ACLs in remap.config can cause a segfault when the user makes a carefully crafted request. This affects versions Apache Traffic Server (ATS) 6.0.0 to 6.2.2 and 7.0.0 to 7.1.3. To resolve this issue users running 6.x should upgrade to 6.2.3 or later versions and 7.x users should upgrade to 7.1.4 or later versions.

In Apache Tika 1.19 (CVE-2018-11761), we added an entity expansion limit for XML parsing. However, Tika reuses SAXParsers and calls reset() after each parse, which, for Xerces2 parsers, as per the documentation, removes the user-specified SecurityManager and thus removes entity expansion limits after the first parse. Apache Tika versions from 0.1 to 1.19 are therefore still vulnerable to entity expansions which can lead to a denial of service attack. Users should upgrade to 1.19.1 or later.

When handling a libprocess message wrapped in 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 crashes if the request path is empty, because the parser assumes the request path always starts with '/'. A malicious actor can therefore cause a denial of service of Mesos masters rendering the Mesos-controlled cluster inoperable.

The REST Plugin in Apache Struts 2.1.x, 2.3.7 through 2.3.33 and 2.5 through 2.5.12 is using an outdated XStream library which is vulnerable and allow perform a DoS attack using malicious request with specially crafted XML payload.

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 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.

In Apache HTTP Server 2.4.53 and earlier, a malicious request to a lua script that calls r:parsebody(0) may cause a denial of service due to no default limit on possible input size.

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.

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.

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 HTTP strict parsing changes added in Apache httpd 2.2.32 and 2.4.24 introduced a bug in token list parsing, which allows ap_find_token() to search past the end of its input string. By maliciously crafting a sequence of request headers, an attacker may be able to cause a segmentation fault, or to force ap_find_token() to return an incorrect value.

There is a DOS attack vulnerability in Apache Traffic Server (ATS) 5.2.0 to 5.3.2, 6.0.0 to 6.2.0, and 7.0.0 with the TLS handshake. This issue can cause the server to coredump.

Apache DolphinScheduler user registration is vulnerable to Regular express Denial of Service (ReDoS) attacks, Apache DolphinScheduler users should upgrade to version 2.0.5 or higher.

In Apache ActiveMQ Artemis prior to 2.20.0 or 2.19.1, an attacker could partially disrupt availability (DoS) through uncontrolled resource consumption of memory.

In 0.9.3 or older versions of Apache Pinot segment upload path allowed segment directories to be imported into pinot tables. In pinot installations that allow open access to the controller a specially crafted request can potentially be exploited to cause disruption in pinot service. Pinot release 0.10.0 fixes this. See https://docs.pinot.apache.org/basics/releases/0.10.0

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.

Apache Struts 2.0.0 through 2.3.4 allows remote attackers to cause a denial of service (CPU consumption) via a long parameter name, which is processed as an OGNL expression.

Apache Traffic Server 6.0.0 to 6.2.0 are affected by an HPACK Bomb Attack.

Apache SpamAssassin 3.0.1, 3.0.2, and 3.0.3 allows remote attackers to cause a denial of service (CPU consumption and slowdown) via a message with a long Content-Type header without any boundaries.

A carefully crafted request body can cause a read to a random memory area which could cause the process to crash. This issue affects Apache HTTP Server 2.4.52 and earlier.

Memory leak in ssl_engine_io.c for mod_ssl in Apache 2 before 2.0.49 allows remote attackers to cause a denial of service (memory consumption) via plain HTTP requests to the SSL port of an SSL-enabled server.

A DNS proxy and possible amplification attack vulnerability in WebClientInfo of Apache Wicket allows an attacker to trigger arbitrary DNS lookups from the server when the X-Forwarded-For header is not properly sanitized. This DNS lookup can be engineered to overload an internal DNS server or to slow down request processing of the Apache Wicket application causing a possible denial of service on either the internal infrastructure or the web application itself. This issue affects Apache Wicket Apache Wicket 9.x version 9.2.0 and prior versions; Apache Wicket 8.x version 8.11.0 and prior versions; Apache Wicket 7.x version 7.17.0 and prior versions and Apache Wicket 6.x version 6.2.0 and later versions.

Unknown vulnerability in mod_python 3.0.x before 3.0.4, and 2.7.x before 2.7.9, allows remote attackers to cause a denial of service (httpd crash) via a certain query string.

The servlet engine in Jakarta Apache Tomcat 3.3 and 4.0.4, when using IIS and the ajp1.3 connector, allows remote attackers to cause a denial of service (crash) via a large number of HTTP GET requests for an MS-DOS device such as AUX, LPT1, CON, or PRN.

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.

A possible interaction between Apple MacOS X release 1.0 and Apache HTTP server allows remote attackers to cause a denial of service (crash) via a flood of HTTP GET requests to CGI programs, which generates a large number of processes.

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.

The ModSecurity module before 2.7.4 for the Apache HTTP Server allows remote attackers to cause a denial of service (NULL pointer dereference, process crash, and disk consumption) via a POST request with a large body and a crafted Content-Type header.