Apache with mod_rewrite enabled on most UNIX systems allows remote attackers to bypass RewriteRules by inserting extra / (slash) characters into the requested path, which causes the regular expression in the RewriteRule to fail.

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.

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.

Apache 1.3.20 on Windows servers allows remote attackers to bypass the default index page and list directory contents via a URL with a large number of / (slash) characters.

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.

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.

Apache NiFi JMS Deserialization issue because of ActiveMQ client vulnerability. Malicious JMS content could cause denial of service. See ActiveMQ CVE-2015-5254 announcement for more information. The fix to upgrade the activemq-client library to 5.15.3 was applied on the Apache NiFi 1.6.0 release. Users running a prior 1.x release should upgrade to the appropriate release.

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.

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).

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 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.

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.

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.

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.

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.

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.

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.

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

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 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.

The fix for bug 63362 present in Apache Tomcat 10.1.0-M1 to 10.1.0-M5, 10.0.0-M1 to 10.0.11, 9.0.40 to 9.0.53 and 8.5.60 to 8.5.71 introduced a memory leak. The object introduced to collect metrics for HTTP upgrade connections was not released for WebSocket connections once the connection was closed. This created a memory leak that, over time, could lead to a denial of service via an OutOfMemoryError.

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.

Improper Input Validation vulnerability in accepting socket connections in Apache Traffic Server allows an attacker to make the server stop accepting new connections. This issue affects Apache Traffic Server 5.0.0 to 9.1.0.

Improper Input Validation vulnerability in Parquet-MR of Apache Parquet allows an attacker to DoS by malicious Parquet files. This issue affects Apache Parquet-MR version 1.9.0 and later versions.

While fuzzing the 2.4.49 httpd, a new null pointer dereference was detected during HTTP/2 request processing, allowing an external source to DoS the server. This requires a specially crafted request. The vulnerability was recently introduced in version 2.4.49. No exploit is known to the project.

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.

The char_buffer_read function in the mod_ssl module for Apache 2.x, when using reverse proxying to an SSL server, allows remote attackers to cause a denial of service (segmentation fault).

The IPv6 URI parsing routines in the apr-util library for Apache 2.0.50 and earlier allow remote attackers to cause a denial of service (child process crash) via a certain URI, as demonstrated using the Codenomicon HTTP Test Tool.

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.

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.

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).

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 Catalina org.apache.catalina.connector.http package in Tomcat 4.0.x up to 4.0.3 allows remote attackers to cause a denial of service via several requests that do not follow the HTTP protocol, which causes Tomcat to reject later requests.

Apache Tomcat 7.0.0 through 7.0.6 and 6.0.0 through 6.0.30 does not enforce the maxHttpHeaderSize limit for requests involving the NIO HTTP connector, which allows remote attackers to cause a denial of service (OutOfMemoryError) via a crafted request.

Apache Tomcat through 7.0.x allows remote attackers to cause a denial of service (daemon outage) via partial HTTP requests, as demonstrated by Slowloris.

The reverse proxy add forward module (mod_rpaf) 0.5 and 0.6 for the Apache HTTP Server allows remote attackers to cause a denial of service (server or application crash) via multiple X-Forwarded-For headers in a request.

The AMQP type decoder in Apache Qpid 0.20 and earlier allows remote attackers to cause a denial of service (memory consumption and server crash) via a large number of zero width elements in the client-properties map in a connection.start-ok message.

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.

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.

The mod_proxy_ajp module in the Apache HTTP Server 2.2.12 through 2.2.21 places a worker node into an error state upon detection of a long request-processing time, which allows remote attackers to cause a denial of service (worker consumption) via an expensive request.

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 Tomcat 6.x before 6.0.37 and 7.x before 7.0.30 does not properly handle chunk extensions in chunked transfer coding, which allows remote attackers to cause a denial of service by streaming data.

The @CopyFrom operation in the POST servlet in the org.apache.sling.servlets.post bundle before 2.1.2 in Apache Sling does not prevent attempts to copy an ancestor node to a descendant node, which allows remote attackers to cause a denial of service (infinite loop) via a crafted HTTP request.

Algorithmic complexity vulnerability in the sorting algorithms in bzip2 compressing stream (BZip2CompressorOutputStream) in Apache Commons Compress before 1.4.1 allows remote attackers to cause a denial of service (CPU consumption) via a file with many repeating inputs.

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.

The UnhandledDataStructure function in hwpf/model/UnhandledDataStructure.java in Apache POI 3.8 and earlier allows remote attackers to cause a denial of service (OutOfMemoryError exception and possibly JVM destabilization) via a crafted length value in a Channel Definition Format (CDF) or Compound File Binary Format (CFBF) document.

tables/apr_hash.c in the Apache Portable Runtime (APR) library through 1.4.5 computes hash values without restricting the ability to trigger hash collisions predictably, which allows context-dependent attackers to cause a denial of service (CPU consumption) via crafted input to an application that maintains a hash table.

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.

Apache Tomcat before 5.5.35, 6.x before 6.0.35, and 7.x before 7.0.23 computes hash values for form parameters without restricting the ability to trigger hash collisions predictably, which allows remote attackers to cause a denial of service (CPU consumption) by sending many crafted parameters.