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.

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.

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.

Unspecified vulnerability in (1) apreq_parse_headers and (2) apreq_parse_urlencoded functions in Apache2::Request (Libapreq2) before 2.07 allows remote attackers to cause a denial of service (CPU consumption) via unknown attack vectors that result in quadratic computational complexity.

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.

When reading a specially crafted ZIP archive, Compress can be made to allocate large amounts of memory that finally leads to an out of memory error even for very small inputs. This could be used to mount a denial of service attack against services that use Compress' zip package.

Memory leak in the worker MPM (worker.c) for Apache 2, in certain circumstances, allows remote attackers to cause a denial of service (memory consumption) via aborted connections, which prevents the memory for the transaction pool from being reused for other connections.

A carefully crafted request uri-path can cause mod_proxy_uwsgi to read above the allocated memory and crash (DoS). This issue affects Apache HTTP Server versions 2.4.30 to 2.4.48 (inclusive).

Apache Tomcat 5.5.0 to 5.5.11 allows remote attackers to cause a denial of service (CPU consumption) via a large number of simultaneous requests to list a web directory that has a large number of files.

The byte-range filter in Apache 2.0 before 2.0.54 allows remote attackers to cause a denial of service (memory consumption) via an HTTP header with a large Range field.

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.

Malformed requests may cause the server to dereference a NULL pointer. This issue affects Apache HTTP Server 2.4.48 and earlier.

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.

fcgid_spawn_ctl.c in the mod_fcgid module 2.3.6 for the Apache HTTP Server does not recognize the FcgidMaxProcessesPerClass directive for a virtual host, which makes it easier for remote attackers to cause a denial of service (memory consumption) via a series of HTTP requests that triggers a process count higher than the intended limit.

An XXE issue in SAXBuilder in JDOM through 2.0.6 allows attackers to cause a denial of service via a crafted HTTP request.

Off-by-one error in the mod_ssl Certificate Revocation List (CRL) verification callback in Apache, when configured to use a CRL, allows remote attackers to cause a denial of service (child process crash) via a CRL that causes a buffer overflow of one null byte.

Apache Tomcat before 5.x allows remote attackers to cause a denial of service (application crash) via a crafted AJP12 packet to TCP port 8007.

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.

Apache HTTP Server protocol handler for the HTTP/2 protocol checks received request headers against the size limitations as configured for the server and used for the HTTP/1 protocol as well. On violation of these restrictions and HTTP response is sent to the client with a status code indicating why the request was rejected. This rejection response was not fully initialised in the HTTP/2 protocol handler if the offending header was the very first one received or appeared in a a footer. This led to a NULL pointer dereference on initialised memory, crashing reliably the child process. Since such a triggering HTTP/2 request is easy to craft and submit, this can be exploited to DoS the server. This issue affected mod_http2 1.15.17 and Apache HTTP Server version 2.4.47 only. Apache HTTP Server 2.4.47 was never released.

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.

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.

Apache mod_auth_radius 1.5.4 and libpam-radius-auth allow remote malicious RADIUS servers to cause a denial of service (crash) via a RADIUS_REPLY_MESSAGE with a RADIUS attribute length of 1, which leads to a memcpy operation with a -1 length argument.

A vulnerability in Apache Tomcat allows an attacker to remotely trigger a denial of service. An error introduced as part of a change to improve error handling during non-blocking I/O meant that the error flag associated with the Request object was not reset between requests. This meant that once a non-blocking I/O error occurred, all future requests handled by that request object would fail. Users were able to trigger non-blocking I/O errors, e.g. by dropping a connection, thereby creating the possibility of triggering a DoS. Applications that do not use non-blocking I/O are not exposed to this vulnerability. This issue affects Apache Tomcat 10.0.3 to 10.0.4; 9.0.44; 8.5.64.

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.

The mod_dav_svn module for the Apache HTTP Server, as distributed in Apache Subversion before 1.6.17, allows remote attackers to cause a denial of service (NULL pointer dereference and daemon crash) via a request for a baselined WebDAV resource, as exploited in the wild in May 2011.

Off-by-one error in the XML signature feature in Apache XML Security for C++ 1.6.0, as used in Shibboleth before 2.4.3 and possibly other products, allows remote attackers to cause a denial of service (crash) via a signature using a large RSA key, which triggers a buffer overflow.

The mod_dav module in Apache 2.0.50 and earlier allows remote attackers to cause a denial of service (child process crash) via a certain sequence of LOCK requests for a location that allows WebDAV authoring access.

Apache 1.4.x before 1.3.30, and 2.0.x before 2.0.49, when using multiple listening sockets on certain platforms, allows remote attackers to cause a denial of service (blocked new connections) via a "short-lived connection on a rarely-accessed listening socket."

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.

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.

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.

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.

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.

Vulnerability in the apr_psprintf function in the Apache Portable Runtime (APR) library for Apache 2.0.37 through 2.0.45 allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via long strings, as demonstrated using XML objects to mod_dav, and possibly other vectors.

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

Jakarta Tomcat before 3.3.1a on certain Windows systems may allow remote attackers to cause a denial of service (thread hang and resource consumption) via a request for a JSP page containing an MS-DOS device name, such as aux.jsp.

Unknown vulnerability in filestat.c for Apache running on OS2, versions 2.0 through 2.0.45, allows unknown attackers to cause a denial of service via requests related to device names.

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 authentication module for Apache 2.0.40 through 2.0.45 on Unix does not properly handle threads safely when using the crypt_r or crypt functions, which allows remote attackers to cause a denial of service (failed Basic authentication with valid usernames and passwords) when a threaded MPM is used.

A memory leak in Apache 2.0 through 2.0.44 allows remote attackers to cause a denial of service (memory consumption) via large chunks of linefeed characters, which causes Apache to allocate 80 bytes for each linefeed.

Apache 2 before 2.0.47, when running on an IPv6 host, allows attackers to cause a denial of service (CPU consumption by infinite loop) when the FTP proxy server fails to create an IPv6 socket.

The rotatelogs program on Apache before 1.3.28, for Windows and OS/2 systems, does not properly ignore certain control characters that are received over the pipe, which could allow remote attackers to cause a denial of service.

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.

mod_cgi in Apache 2.0.39 and 2.0.40 allows local users and possibly remote attackers to cause a denial of service (hang and memory consumption) by causing a CGI script to send a large amount of data to stderr, which results in a read/write deadlock between httpd and the CGI script.

Unknown vulnerability in Apache 1.3.19 running on HP Secure OS for Linux 1.0 allows remote attackers to cause "unexpected results" via an HTTP request.