In Apache Qpid Broker-J versions 6.1.0 through 6.1.4 (inclusive) the broker does not properly enforce a maximum frame size in AMQP 1.0 frames. A remote unauthenticated attacker could exploit this to cause the broker to exhaust all available memory and eventually terminate. Older AMQP protocols are not affected.

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.

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

Apache before 1.3.20 on Windows and OS/2 systems allows remote attackers to cause a denial of service (GPF) via an HTTP request for a URI that contains a large number of / (slash) or other characters, which causes certain functions to dereference a null pointer.

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.

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.

Memory leak in the apr_brigade_split_line function in buckets/apr_brigade.c in the Apache Portable Runtime Utility library (aka APR-util) before 1.3.10, as used in the mod_reqtimeout module in the Apache HTTP Server and other software, allows remote attackers to cause a denial of service (memory consumption) via unspecified vectors related to the destruction of an APR bucket.

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 Cluster::deliveredEvent function in cluster/Cluster.cpp in Apache Qpid, as used in Red Hat Enterprise MRG before 1.3 and other products, allows remote attackers to cause a denial of service (daemon crash and cluster outage) via invalid AMQP data.

The big2_toUtf8 function in lib/xmltok.c in libexpat in Expat 2.0.1, as used in the XML-Twig module for Perl, allows context-dependent attackers to cause a denial of service (application crash) via an XML document with malformed UTF-8 sequences that trigger a buffer over-read, related to the doProlog function in lib/xmlparse.c, a different vulnerability than CVE-2009-2625 and CVE-2009-3720.

The Solaris pollset feature in the Event Port backend in poll/unix/port.c in the Apache Portable Runtime (APR) library before 1.3.9, as used in the Apache HTTP Server before 2.2.14 and other products, does not properly handle errors, which allows remote attackers to cause a denial of service (daemon hang) via unspecified HTTP requests, related to the prefork and event MPMs.

CXF supports (via JwtRequestCodeFilter) passing OAuth 2 parameters via a JWT token as opposed to query parameters (see: The OAuth 2.0 Authorization Framework: JWT Secured Authorization Request (JAR)). Instead of sending a JWT token as a "request" parameter, the spec also supports specifying a URI from which to retrieve a JWT token from via the "request_uri" parameter. CXF was not validating the "request_uri" parameter (apart from ensuring it uses "https) and was making a REST request to the parameter in the request to retrieve a token. This means that CXF was vulnerable to DDos attacks on the authorization server, as specified in section 10.4.1 of the spec. This issue affects Apache CXF versions prior to 3.4.3; Apache CXF versions prior to 3.3.10.

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.

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.

XMLScanner.java in Apache Xerces2 Java, as used in Sun Java Runtime Environment (JRE) in JDK and JRE 6 before Update 15 and JDK and JRE 5.0 before Update 20, and in other products, allows remote attackers to cause a denial of service (infinite loop and application hang) via malformed XML input, as demonstrated by the Codenomicon XML fuzzing framework.

Apache webserver 2.0.52 and earlier allows remote attackers to cause a denial of service (CPU consumption) via an HTTP GET request with a MIME header containing multiple lines with a large number of space characters.

Some HTTP/2 implementations are vulnerable to resource loops, potentially leading to a denial of service. The attacker creates multiple request streams and continually shuffles the priority of the streams in a way that causes substantial churn to the priority tree. This can consume excess CPU.

Some HTTP/2 implementations are vulnerable to a settings flood, potentially leading to a denial of service. The attacker sends a stream of SETTINGS frames to the peer. Since the RFC requires that the peer reply with one acknowledgement per SETTINGS frame, an empty SETTINGS frame is almost equivalent in behavior to a ping. Depending on how efficiently this data is queued, this can consume excess CPU, memory, or both.

Some HTTP/2 implementations are vulnerable to window size manipulation and stream prioritization manipulation, potentially leading to a denial of service. The attacker requests a large amount of data from a specified resource over multiple streams. They manipulate window size and stream priority to force the server to queue the data in 1-byte chunks. Depending on how efficiently this data is queued, this can consume excess CPU, memory, or both.

Some HTTP/2 implementations are vulnerable to a flood of empty frames, potentially leading to a denial of service. The attacker sends a stream of frames with an empty payload and without the end-of-stream flag. These frames can be DATA, HEADERS, CONTINUATION and/or PUSH_PROMISE. The peer spends time processing each frame disproportionate to attack bandwidth. This can consume excess CPU.

Some HTTP/2 implementations are vulnerable to a reset flood, potentially leading to a denial of service. The attacker opens a number of streams and sends an invalid request over each stream that should solicit a stream of RST_STREAM frames from the peer. Depending on how the peer queues the RST_STREAM frames, this can consume excess memory, CPU, or both.

Some HTTP/2 implementations are vulnerable to unconstrained interal data buffering, potentially leading to a denial of service. The attacker opens the HTTP/2 window so the peer can send without constraint; however, they leave the TCP window closed so the peer cannot actually write (many of) the bytes on the wire. The attacker then sends a stream of requests for a large response object. Depending on how the servers queue the responses, this can consume excess memory, CPU, or both.

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.

Some HTTP/2 implementations are vulnerable to ping floods, potentially leading to a denial of service. The attacker sends continual pings to an HTTP/2 peer, causing the peer to build an internal queue of responses. Depending on how efficiently this data is queued, this can consume excess CPU, memory, or both.

Some HTTP/2 implementations are vulnerable to a header leak, potentially leading to a denial of service. The attacker sends a stream of headers with a 0-length header name and 0-length header value, optionally Huffman encoded into 1-byte or greater headers. Some implementations allocate memory for these headers and keep the allocation alive until the session dies. This can consume excess memory.

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.

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.

The Java Server Pages (JSP) engine in Tomcat allows web page owners to cause a denial of service (engine crash) on the web server via a JSP page that calls WPrinterJob().pageSetup(null,null).

Buffer overflow in Apache 1.2.5 and earlier allows a remote attacker to cause a denial of service with a large number of GET requests containing a large number of / characters.

cyrus-sasl (aka Cyrus SASL) 2.1.27 has an out-of-bounds write leading to unauthenticated remote denial-of-service in OpenLDAP via a malformed LDAP packet. The OpenLDAP crash is ultimately caused by an off-by-one error in _sasl_add_string in common.c in cyrus-sasl.

The AsyncResponseWrapperImpl class in Apache Olingo versions 4.0.0 to 4.6.0 reads the Retry-After header and passes it to the Thread.sleep() method without any check. If a malicious server returns a huge value in the header, then it can help to implement a DoS attack.

The mod_http2 module in the Apache HTTP Server 2.4.17 through 2.4.23, when the Protocols configuration includes h2 or h2c, does not restrict request-header length, which allows remote attackers to cause a denial of service (memory consumption) via crafted CONTINUATION frames in an HTTP/2 request.

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 HTTP/2 header parser in Apache Tomcat 9.0.0.M1 to 9.0.0.M11 and 8.5.0 to 8.5.6 entered an infinite loop if a header was received that was larger than the available buffer. This made a denial of service attack possible.

The ASN.1 parser in Bouncy Castle Crypto (aka BC Java) 1.63 can trigger a large attempted memory allocation, and resultant OutOfMemoryError error, via crafted ASN.1 data. This is fixed in 1.64.

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

Stack-based buffer overflow in Apache Xerces-C++ before 3.1.4 allows context-dependent attackers to cause a denial of service via a deeply nested DTD.

The URLValidator class in Apache Struts 2 2.3.20 through 2.3.28.1 and 2.5.x before 2.5.1 allows remote attackers to cause a denial of service via a null value for a URL field.

The MultipartStream class in Apache Commons Fileupload before 1.3.2, as used in Apache Tomcat 7.x before 7.0.70, 8.x before 8.0.36, 8.5.x before 8.5.3, and 9.x before 9.0.0.M7 and other products, allows remote attackers to cause a denial of service (CPU consumption) via a long boundary string.

Apache Struts 2.0.0 through 2.3.24.1 does not properly cache method references when used with OGNL before 3.0.12, which allows remote attackers to cause a denial of service (block access to a web site) via unspecified vectors.

In Apache HTTP Server versions 2.4.0 to 2.4.23, malicious input to mod_auth_digest can cause the server to crash, and each instance continues to crash even for subsequently valid requests.

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.

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.

Application plugins in Apache CXF Fediz before 1.1.3 and 1.2.x before 1.2.1 allow remote attackers to cause a denial of service.