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.

In Apache HTTP server versions 2.4.37 and prior, by sending request bodies in a slow loris way to plain resources, the h2 stream for that request unnecessarily occupied a server thread cleaning up that incoming data. This affects only HTTP/2 (mod_http2) connections.

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.

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.

By specially crafting HTTP/2 requests, workers would be allocated 60 seconds longer than necessary, leading to worker exhaustion and a denial of service. Fixed in Apache HTTP Server 2.4.34 (Affected 2.4.18-2.4.30,2.4.33).

Apache Xerces-C++ allows remote attackers to cause a denial of service (CPU consumption) via a crafted message sent to an XML service that causes hash table collisions.

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.

A flaw was discovered in OpenLDAP before 2.4.57 leading in an assertion failure in slapd in the X.509 DN parsing in decode.c ber_next_element, resulting in denial of service.

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.

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.

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.

In Apache httpd 2.0.23 to 2.0.65, 2.2.0 to 2.2.34, and 2.4.0 to 2.4.29, mod_authnz_ldap, if configured with AuthLDAPCharsetConfig, uses the Accept-Language header value to lookup the right charset encoding when verifying the user's credentials. If the header value is not present in the charset conversion table, a fallback mechanism is used to truncate it to a two characters value to allow a quick retry (for example, 'en-US' is truncated to 'en'). A header value of less than two characters forces an out of bound write of one NUL byte to a memory location that is not part of the string. In the worst case, quite unlikely, the process would crash which could be used as a Denial of Service attack. In the more likely case, this memory is already reserved for future use and the issue has no effect at all.

Apache Traffic Server 2.0.x and 3.0.x before 3.0.4 and 3.1.x before 3.1.3 does not properly allocate heap memory, which allows remote attackers to cause a denial of service (daemon crash) via a long HTTP Host header.

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.

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.

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.

Apache Traffic Server 9.0.0 is vulnerable to a remote DOS attack on the experimental Slicer plugin.

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.

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 OpenMeetings 1.0.0 doesn't check contents of files being uploaded. An attacker can cause a denial of service by uploading multiple large files to the server.

A vulnerability in the .NET SDK of Apache Avro allows an attacker to allocate excessive resources, potentially causing a denial-of-service attack. This issue affects .NET applications using Apache Avro version 1.10.2 and prior versions. Users should update to version 1.11.0 which addresses this issue.

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.

A maliciously constructed HTTP/2 request could cause mod_http2 in Apache HTTP Server 2.4.24, 2.4.25 to dereference a NULL pointer and crash the server process.

In Apache Thrift 0.9.3 to 0.13.0, malicious RPC clients could send short messages which would result in a large memory allocation, potentially leading to denial of service.

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.

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.

Apache HTTP Server versions 2.4.41 to 2.4.46 mod_proxy_http can be made to crash (NULL pointer dereference) with specially crafted requests using both Content-Length and Transfer-Encoding headers, leading to a Denial of Service

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 Traffic Server before 6.2.1 generates a coredump when there is a mismatch between content length and chunked encoding.

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 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.

Apache Xerces2 Java Parser before 2.12.0 allows remote attackers to cause a denial of service (CPU consumption) via a crafted message to an XML service, which triggers hash table collisions.

cache_util.c in the mod_cache module in Apache HTTP Server (httpd), when caching is enabled and a threaded Multi-Processing Module (MPM) is used, allows remote attackers to cause a denial of service (child processing handler crash) via a request with the (1) s-maxage, (2) max-age, (3) min-fresh, or (4) max-stale Cache-Control headers without a value.

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.

A denial of service vulnerability was identified that exists in Apache SpamAssassin before 3.4.2. The vulnerability arises with certain unclosed tags in emails that cause markup to be handled incorrectly leading to scan timeouts. In Apache SpamAssassin, using HTML::Parser, we setup an object and hook into the begin and end tag event handlers In both cases, the "open" event is immediately followed by a "close" event - even if the tag *does not* close in the HTML being parsed. Because of this, we are missing the "text" event to deal with the object normally. This can cause carefully crafted emails that might take more scan time than expected leading to a Denial of Service. The issue is possibly a bug or design decision in HTML::Parser that specifically impacts the way Apache SpamAssassin uses the module with poorly formed html. The exploit has been seen in the wild but not believed to have been purposefully part of a Denial of Service attempt. We are concerned that there may be attempts to abuse the vulnerability in the future.

In Apache Struts 2.5 to 2.5.14, the REST Plugin is using an outdated JSON-lib library which is vulnerable and allow perform a DoS attack using malicious request with specially crafted JSON payload.

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.

Apache POI in versions prior to release 3.17 are vulnerable to Denial of Service Attacks: 1) Infinite Loops while parsing crafted WMF, EMF, MSG and macros (POI bugs 61338 and 61294), and 2) Out of Memory Exceptions while parsing crafted DOC, PPT and XLS (POI bugs 52372 and 61295).

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 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.

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 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 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 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 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.

Format string vulnerability in LocalSyslogAppender in Apache log4net 1.2.9 might allow remote attackers to cause a denial of service (memory corruption and termination) via unknown vectors.

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

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.