Multiple denial-of-service attacks that can be triggered by writing to the terminal exist in PuTTY versions before 0.71.

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.

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.

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.

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.

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.

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.

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 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 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.

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.

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).

A denial of service flaw was found in OpenSSL 0.9.8, 1.0.1, 1.0.2 through 1.0.2h, and 1.1.0 in the way the TLS/SSL protocol defined processing of ALERT packets during a connection handshake. A remote attacker could use this flaw to make a TLS/SSL server consume an excessive amount of CPU and fail to accept connections from other clients.

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 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 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.

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).

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.

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.

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.

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.

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 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.

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.

An issue was discovered in the protobuf crate before 2.6.0 for Rust. Attackers can exhaust all memory via Vec::reserve calls.

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.

The streaming XML parser in Apache CXF 2.5.x before 2.5.10, 2.6.x before 2.6.7, and 2.7.x before 2.7.4 allows remote attackers to cause a denial of service (CPU and memory consumption) via crafted XML with a large number of (1) elements, (2) attributes, (3) nested constructs, and possibly other vectors.

The mod_dav_svn Apache HTTPD server module in Subversion 1.7.0 through 1.7.8 allows remote attackers to cause a denial of service (segmentation fault and crash) via a log REPORT request with an invalid limit, which triggers an access of an uninitialized variable.

The deepGetOrCreateNode function in impl/operations/AbstractCreateOperation.java in org.apache.sling.servlets.post.bundle 2.2.0 and 2.3.0 in Apache Sling does not properly handle a NULL value that returned when the session does not have permissions to the root node, which allows remote attackers to cause a denial of service (infinite loop) via unspecified vectors.

The mod_dav_svn Apache HTTPD server module in Subversion 1.6.0 through 1.6.20 and 1.7.0 through 1.7.8 allows remote attackers to cause a denial of service (NULL pointer dereference and crash) via an anonymous LOCK for a URL that does not exist.

In FreeBSD 12.0-STABLE before r350637, 12.0-RELEASE before 12.0-RELEASE-p9, 11.3-STABLE before r350638, 11.3-RELEASE before 11.3-RELEASE-p2, and 11.2-RELEASE before 11.2-RELEASE-p13, the bsnmp library is not properly validating the submitted length from a type-length-value encoding. A remote user could cause an out-of-bounds read or trigger a crash of the software such as bsnmpd resulting in a denial of service.

Clustered Data ONTAP versions 9.2 through 9.4 are susceptible to a vulnerability which allows an attacker to use l2ping to cause a Denial of Service (DoS).

Certain versions of the NetApp Service Processor and Baseboard Management Controller firmware allow a remote unauthenticated attacker to cause a Denial of Service (DoS).

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.

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 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.

libcurl versions from 7.34.0 to before 7.64.0 are vulnerable to a heap out-of-bounds read in the code handling the end-of-response for SMTP. If the buffer passed to `smtp_endofresp()` isn't NUL terminated and contains no character ending the parsed number, and `len` is set to 5, then the `strtol()` call reads beyond the allocated buffer. The read contents will not be returned to the caller.

Apache Tomcat 4.0.3, and possibly other versions before 4.1.3 beta, allows remote attackers to cause a denial of service (resource exhaustion) via a large number of requests to the server with null characters, which causes the working threads to hang.

In Lib/tarfile.py in Python through 3.8.3, an attacker is able to craft a TAR archive leading to an infinite loop when opened by tarfile.open, because _proc_pax lacks header validation.

xmlParseBalancedChunkMemoryRecover in parser.c in libxml2 before 2.9.10 has a memory leak related to newDoc->oldNs.

A flaw was found in Undertow when using Remoting as shipped in Red Hat Jboss EAP before version 7.2.4. A memory leak in HttpOpenListener due to holding remote connections indefinitely may lead to denial of service. Versions before undertow 2.0.25.SP1 and jboss-remoting 5.0.14.SP1 are believed to be vulnerable.

SQLite 3.30.1 mishandles certain SELECT statements with a nonexistent VIEW, leading to an application crash.

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.

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.

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.

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.