Uncontrolled Resource Consumption ('Resource Exhaustion')
|ID: 400||Date: (C)2012-05-14 (M)2018-02-16|
|Type: weakness||Status: INCOMPLETE|
|Abstraction Type: Base|
The software does not properly restrict the size or amount of
resources that are requested or influenced by an actor, which can be used to
consume more resources than intended.
Extended DescriptionLimited resources include memory, file system storage, database connection
pool entries, or CPU. If an attacker can trigger the allocation of these
limited resources, but the number or size of the resources is not
controlled, then the attacker could cause a denial of service that consumes
all available resources. This would prevent valid users from accessing the
software, and it could potentially have an impact on the surrounding
environment. For example, a memory exhaustion attack against an application
could slow down the application as well as its host operating system.Resource exhaustion problems have at least two common causes:Error conditions and other exceptional circumstancesConfusion over which part of the program is responsible for releasing
Likelihood of Exploit: Medium to High
Applicable PlatformsLanguage Class: All
Time Of Introduction
- Architecture and Design
Related Attack Patterns
|Availability ||DoS: crash / exit /
restartDoS: resource consumption
(CPU)DoS: resource consumption
(memory)DoS: resource consumption
(other) ||The most common result of resource exhaustion is denial of service.
The software may slow down, crash due to unhandled errors, or lock out
legitimate users. |
|Access_ControlOther ||Bypass protection
mechanismOther ||In some cases it may be possible to force the software to "fail open"
in the event of resource exhaustion. The state of the software -- and
possibly the security functionality - may then be compromised. |
|Automated Static Analysis ||Automated static analysis typically has limited utility in recognizing
resource exhaustion problems, except for program-independent system
resources such as files, sockets, and processes. For system resources,
automated static analysis may be able to detect circumstances in which
resources are not released after they have expired. Automated analysis
of configuration files may be able to detect settings that do not
specify a maximum value.Automated static analysis tools will not be appropriate for detecting
exhaustion of custom resources, such as an intended security policy in
which a bulletin board user is only allowed to make a limited number of
posts per day. ||Limited || |
|Automated Dynamic Analysis ||Certain automated dynamic analysis techniques may be effective in
spotting resource exhaustion problems, especially with resources such as
processes, memory, and connections. The technique may involve generating
a large number of requests to the software within a short time
frame. ||Moderate || |
|Fuzzing ||While fuzzing is typically geared toward finding low-level
implementation bugs, it can inadvertently find resource exhaustion
problems. This can occur when the fuzzer generates a large number of
test cases but does not restart the targeted software in between test
cases. If an individual test case produces a crash, but it does not do
so reliably, then an inability to handle resource exhaustion may be the
cause. ||Opportunistic || |
|Architecture and Design || ||Design throttling mechanisms into the system architecture. The best
protection is to limit the amount of resources that an unauthorized user
can cause to be expended. A strong authentication and access control
model will help prevent such attacks from occurring in the first place.
The login application should be protected against DoS attacks as much as
possible. Limiting the database access, perhaps by caching result sets,
can help minimize the resources expended. To further limit the potential
for a DoS attack, consider tracking the rate of requests received from
users and blocking requests that exceed a defined rate threshold. || || |
|Architecture and Design || ||Mitigation of resource exhaustion attacks requires that the target
system either:The first of these solutions is an issue in itself though, since it
may allow attackers to prevent the use of the system by a particular
valid user. If the attacker impersonates the valid user, he may be able
to prevent the user from accessing the server in question.The second solution is simply difficult to effectively institute --
and even when properly done, it does not provide a full solution. It
simply makes the attack require more resources on the part of the
attacker. || || |
|Architecture and Design || ||Ensure that protocols have specific limits of scale placed on
them. || || |
|Implementation || ||Ensure that all failures in resource allocation place the system into
a safe posture. || || |
|CWE-400 ChildOf CWE-892 ||Category ||CWE-888 || |
Demonstrative Examples (Details)
- In the following example a server socket connection is used to
accept a request to store data on the local file system using a specified
filename. The method openSocketConnection establishes a server socket to
accept requests from a client. When a client establishes a connection to
this service the getNextMessage method is first used to retrieve from the
socket the name of the file to store the data, the openFileToWrite method
will validate the filename and open a file to write to on the local file
system. The getNextMessage is then used within a while loop to continuously
read data from the socket and output the data to the file until there is no
longer any data from the socket. (Demonstrative Example Id DX-50)
- In the following example, a server object creates a server socket
and accepts client connections to the socket. For every client connection to
the socket a separate thread object is generated using the
ClientSocketThread class that handles request made by the client through the
socket. (Demonstrative Example Id DX-52)
- In the following example, the processMessage method receives a two
dimensional character array containing the message to be processed. The
two-dimensional character array contains the length of the message in the
first character array and the message body in the second character array.
The getMessageLength method retrieves the integer value of the length from
the first character array. After validating that the message length is
greater than zero, the body character array pointer points to the start of
the second character array of the two-dimensional character array and memory
is allocated for the new body character array. (Demonstrative Example Id DX-51)
- This code allocates a socket and forks each time it receives a new
connection. (Demonstrative Example Id DX-25)
- CVE-2009-2874 : Product allows attackers to cause a crash via a large number of connections.
- CVE-2009-1928 : Malformed request triggers uncontrolled recursion, leading to stack exhaustion.
- CVE-2009-2858 : Chain: memory leak (CWE-404) leads to resource exhaustion.
- CVE-2009-2726 : Driver does not use a maximum width when invoking sscanf style functions, causing stack consumption.
- CVE-2009-2540 : Large integer value for a length property in an object causes a large amount of memory allocation.
- CVE-2009-2299 : Web application firewall consumes excessive memory when an HTTP request contains a large Content-Length value but no POST data.
- CVE-2009-2054 : Product allows exhaustion of file descriptors when processing a large number of TCP packets.
- CVE-2008-5180 : Communication product allows memory consumption with a large number of SIP requests, which cause many sessions to be created.
- CVE-2008-2121 : TCP implementation allows attackers to consume CPU and prevent new connections using a TCP SYN flood attack.
- CVE-2008-2122 : Port scan triggers CPU consumption with processes that attempt to read data from closed sockets.
- CVE-2008-1700 : Product allows attackers to cause a denial of service via a large number of directives, each of which opens a separate window.
- CVE-2007-4103 : Product allows resource exhaustion via a large number of calls that do not complete a 3-way handshake.
- CVE-2006-1173 : Mail server does not properly handle deeply nested multipart MIME messages, leading to stack exhaustion.
- CVE-2007-0897 : Chain: anti-virus product encounters a malformed file but returns from a function without closing a file descriptor (CWE-775) leading to file descriptor consumption (CWE-400) and failed scans.
For more examples, refer to CVE relations in the bottom box.
White Box Definitions None
Black Box Definitions None
|CLASP || ||Resource exhaustion (file descriptor, disk space, sockets,
...) || |
|OWASP Top Ten 2004 ||A9 ||Denial of Service ||CWE_More_Specific |
|WASC ||10 ||Denial of Service || |
|WASC ||41 ||XML Attribute Blowup || |
|CERT Java Secure Coding ||SER12-J ||Avoid memory and resource leaks during
serialization || |
|CERT Java Secure Coding ||MSC05-J ||Do not exhaust heap space || |
- Joao Antunes Nuno Ferreira Neves Paulo Verissimo .Detection and Prediction of Resource-Exhaustion
Vulnerabilities. Proceedings of the IEEE International Symposium on
Software Reliability Engineering (ISSRE). Published on November 2008.
- D.J. Bernstein .Resource exhaustion.
- Pascal Meunier .Resource exhaustion. Secure Programming Educational
Material. Published on 2004.
- M. Howard D. LeBlanc .Writing Secure Code 2nd Edition. Microsoft. Section:'Chapter 17, "Protecting Against Denial of Service Attacks"
Page 517'. Published on 2002.