Common Attack Pattern Enumeration and Classification
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CAPEC-32: XSS Through HTTP Query Strings
An adversary embeds malicious script code in the parameters of an HTTP query string and convinces a victim to submit the HTTP request that contains the query string to a vulnerable web application. The web application then procedes to use the values parameters without properly validation them first and generates the HTML code that will be executed by the victim's browser.
CAPEC-320: TCP Timestamp Probe
This OS fingerprinting probe examines the remote server's implementation of TCP timestamps. Not all operating systems implement timestamps within the TCP header, but when timestamps are used then this provides the attacker with a means to guess the operating system of the target. The attacker begins by probing any active TCP service in order to get response which contains a TCP timestamp. Different Operating systems update the timestamp value using different intervals. This type of analysis is most accurate when multiple timestamp responses are received and then analyzed. TCP timestamps can be found in the TCP Options field of the TCP header.
CAPEC-321: TCP Sequence Number Probe
This OS fingerprinting probe tests the target system's assignment of TCP sequence numbers. One common way to test TCP Sequence Number generation is to send a probe packet to an open port on the target and then compare the how the Sequence Number generated by the target relates to the Acknowledgement Number in the probe packet. Different operating systems assign Sequence Numbers differently, so a fingerprint of the operating system can be obtained by categorizing the relationship between the acknowledgement number and sequence number as follows: 1) the Sequence Number generated by the target is Zero, 2) the Sequence Number generated by the target is the same as the acknowledgement number in the probe, 3) the Sequence Number generated by the target is the acknowledgement number plus one, or 4) the Sequence Number is any other non-zero number.
CAPEC-322: TCP (ISN) Greatest Common Divisor Probe
This OS fingerprinting probe sends a number of TCP SYN packets to an open port of a remote machine. The Initial Sequence Number (ISN) in each of the SYN/ACK response packets is analyzed to determine the smallest number that the target host uses when incrementing sequence numbers. This information can be useful for identifying an operating system because particular operating systems and versions increment sequence numbers using different values. The result of the analysis is then compared against a database of OS behaviors to determine the OS type and/or version.
CAPEC-323: TCP (ISN) Counter Rate Probe
This OS detection probe measures the average rate of initial sequence number increments during a period of time. Sequence numbers are incremented using a time-based algorithm and are susceptible to a timing analysis that can determine the number of increments per unit time. The result of this analysis is then compared against a database of operating systems and versions to determine likely operation system matches.
CAPEC-324: TCP (ISN) Sequence Predictability Probe
This type of operating system probe attempts to determine an estimate for how predictable the sequence number generation algorithm is for a remote host. Statistical techniques, such as standard deviation, can be used to determine how predictable the sequence number generation is for a system. This result can then be compared to a database of operating system behaviors to determine a likely match for operating system and version.
CAPEC-325: TCP Congestion Control Flag (ECN) Probe
This OS fingerprinting probe checks to see if the remote host supports explicit congestion notification (ECN) messaging. ECN messaging was designed to allow routers to notify a remote host when signal congestion problems are occurring. Explicit Congestion Notification messaging is defined by RFC 3168. Different operating systems and versions may or may not implement ECN notifications, or may respond uniquely to particular ECN flag types.
CAPEC-326: TCP Initial Window Size Probe
This OS fingerprinting probe checks the initial TCP Window size. TCP stacks limit the range of sequence numbers allowable within a session to maintain the connected state within TCP protocol logic. The initial window size specifies a range of acceptable sequence numbers that will qualify as a response to an ACK packet within a session. Various operating systems use different Initial window sizes. The initial window size can be sampled by establishing an ordinary TCP connection.
CAPEC-327: TCP Options Probe
This OS fingerprinting probe analyzes the type and order of any TCP header options present within a response segment. Most operating systems use unique ordering and different option sets when options are present. RFC 793 does not specify a required order when options are present, so different implementations use unique ways of ordering or structuring TCP options. TCP options can be generated by ordinary TCP traffic.
CAPEC-328: TCP 'RST' Flag Checksum Probe
This OS fingerprinting probe performs a checksum on any ASCII data contained within the data portion or a RST packet. Some operating systems will report a human-readable text message in the payload of a 'RST' (reset) packet when specific types of connection errors occur. RFC 1122 allows text payloads within reset packets but not all operating systems or routers implement this functionality.
CAPEC-329: ICMP Error Message Quoting Probe
An adversary uses a technique to generate an ICMP Error message (Port Unreachable, Destination Unreachable, Redirect, Source Quench, Time Exceeded, Parameter Problem) from a target and then analyze the amount of data returned or Quoted from the originating request that generated the ICMP error message.
CAPEC-33: HTTP Request Smuggling
An adversary abuses the flexibility and discrepancies in the parsing and interpretation of HTTP Request messages using various HTTP headers, request-line and body parameters as well as message sizes (denoted by the end of message signaled by a given HTTP header) by different intermediary HTTP agents (e.g., load balancer, reverse proxy, web caching proxies, application firewalls, etc.) to secretly send unauthorized and malicious HTTP requests to a back-end HTTP agent (e.g., web server). See CanPrecede relationships for possible consequences.
CAPEC-330: ICMP Error Message Echoing Integrity Probe
An adversary uses a technique to generate an ICMP Error message (Port Unreachable, Destination Unreachable, Redirect, Source Quench, Time Exceeded, Parameter Problem) from a target and then analyze the integrity of data returned or Quoted from the originating request that generated the error message.
CAPEC-331: ICMP IP Total Length Field Probe
An adversary sends a UDP packet to a closed port on the target machine to solicit an IP Header's total length field value within the echoed 'Port Unreachable error message. This type of behavior is useful for building a signature-base of operating system responses, particularly when error messages contain other types of information that is useful identifying specific operating system responses.
CAPEC-332: ICMP IP 'ID' Field Error Message Probe
An adversary sends a UDP datagram having an assigned value to its internet identification field (ID) to a closed port on a target to observe the manner in which this bit is echoed back in the ICMP error message. This allows the attacker to construct a fingerprint of specific OS behaviors.
CAPEC-34: HTTP Response Splitting
An adversary manipulates and injects malicious content, in the form of secret unauthorized HTTP responses, into a single HTTP response from a vulnerable or compromised back-end HTTP agent (e.g., web server) or into an already spoofed HTTP response from an adversary controlled domain/site. See CanPrecede relationships for possible consequences.
CAPEC-35: Leverage Executable Code in Non-Executable Files
An attack of this type exploits a system's trust in configuration and resource files. When the executable loads the resource (such as an image file or configuration file) the attacker has modified the file to either execute malicious code directly or manipulate the target process (e.g. application server) to execute based on the malicious configuration parameters. Since systems are increasingly interrelated mashing up resources from local and remote sources the possibility of this attack occurring is high.
CAPEC-36: Using Unpublished Interfaces or Functionality
An adversary searches for and invokes interfaces or functionality that the target system designers did not intend to be publicly available. If interfaces fail to authenticate requests, the attacker may be able to invoke functionality they are not authorized for.
CAPEC-37: Retrieve Embedded Sensitive Data
An attacker examines a target system to find sensitive data that has been embedded within it. This information can reveal confidential contents, such as account numbers or individual keys/credentials that can be used as an intermediate step in a larger attack.
CAPEC-38: Leveraging/Manipulating Configuration File Search Paths
This pattern of attack sees an adversary load a malicious resource into a program's standard path so that when a known command is executed then the system instead executes the malicious component. The adversary can either modify the search path a program uses, like a PATH variable or classpath, or they can manipulate resources on the path to point to their malicious components. J2EE applications and other component based applications that are built from multiple binaries can have very long list of dependencies to execute. If one of these libraries and/or references is controllable by the attacker then application controls can be circumvented by the attacker.
CAPEC-383: Harvesting Information via API Event Monitoring
An adversary hosts an event within an application framework and then monitors the data exchanged during the course of the event for the purpose of harvesting any important data leaked during the transactions. One example could be harvesting lists of usernames or userIDs for the purpose of sending spam messages to those users. One example of this type of attack involves the adversary creating an event within the sub-application. Assume the adversary hosts a virtual sale of rare items. As other users enter the event, the attacker records via AiTM (CAPEC-94) proxy the user_ids and usernames of everyone who attends. The adversary would then be able to spam those users within the application using an automated script.
CAPEC-384: Application API Message Manipulation via Man-in-the-Middle
An attacker manipulates either egress or ingress data from a client within an application framework in order to change the content of messages. Performing this attack can allow the attacker to gain unauthorized privileges within the application, or conduct attacks such as phishing, deceptive strategies to spread malware, or traditional web-application attacks. The techniques require use of specialized software that allow the attacker to perform adversary-in-the-middle (CAPEC-94) communications between the web browser and the remote system. Despite the use of AiTH software, the attack is actually directed at the server, as the client is one node in a series of content brokers that pass information along to the application framework. Additionally, it is not true Adversary-in-the-Middle attack at the network layer, but an application-layer attack the root cause of which is the master applications trust in the integrity of code supplied by the client.
CAPEC-385: Transaction or Event Tampering via Application API Manipulation
An attacker hosts or joins an event or transaction within an application framework in order to change the content of messages or items that are being exchanged. Performing this attack allows the attacker to manipulate content in such a way as to produce messages or content that look authentic but may contain deceptive links, substitute one item or another, spoof an existing item and conduct a false exchange, or otherwise change the amounts or identity of what is being exchanged. The techniques require use of specialized software that allow the attacker to man-in-the-middle communications between the web browser and the remote system in order to change the content of various application elements. Often, items exchanged in game can be monetized via sales for coin, virtual dollars, etc. The purpose of the attack is for the attack to scam the victim by trapping the data packets involved the exchange and altering the integrity of the transfer process.
CAPEC-386: Application API Navigation Remapping
An attacker manipulates either egress or ingress data from a client within an application framework in order to change the destination and/or content of links/buttons displayed to a user within API messages. Performing this attack allows the attacker to manipulate content in such a way as to produce messages or content that looks authentic but contains links/buttons that point to an attacker controlled destination. Some applications make navigation remapping more difficult to detect because the actual HREF values of images, profile elements, and links/buttons are masked. One example would be to place an image in a user's photo gallery that when clicked upon redirected the user to an off-site location. Also, traditional web vulnerabilities (such as CSRF) can be constructed with remapped buttons or links. In some cases navigation remapping can be used for Phishing attacks or even means to artificially boost the page view, user site reputation, or click-fraud.
CAPEC-387: Navigation Remapping To Propagate Malicious Content
An adversary manipulates either egress or ingress data from a client within an application framework in order to change the content of messages and thereby circumvent the expected application logic.
CAPEC-388: Application API Button Hijacking
An attacker manipulates either egress or ingress data from a client within an application framework in order to change the destination and/or content of buttons displayed to a user within API messages. Performing this attack allows the attacker to manipulate content in such a way as to produce messages or content that looks authentic but contains buttons that point to an attacker controlled destination.
CAPEC-389: Content Spoofing Via Application API Manipulation
An attacker manipulates either egress or ingress data from a client within an application framework in order to change the content of messages. Performing this attack allows the attacker to manipulate content in such a way as to produce messages or content that look authentic but may contain deceptive links, spam-like content, or links to the attackers' code. In general, content-spoofing within an application API can be employed to stage many different types of attacks varied based on the attackers' intent. The techniques require use of specialized software that allow the attacker to use adversary-in-the-middle (CAPEC-94) communications between the web browser and the remote system.
CAPEC-39: Manipulating Opaque Client-based Data Tokens
In circumstances where an application holds important data client-side in tokens (cookies, URLs, data files, and so forth) that data can be manipulated. If client or server-side application components reinterpret that data as authentication tokens or data (such as store item pricing or wallet information) then even opaquely manipulating that data may bear fruit for an Attacker. In this pattern an attacker undermines the assumption that client side tokens have been adequately protected from tampering through use of encryption or obfuscation.
CAPEC-390: Bypassing Physical Security
Facilities often used layered models for physical security such as traditional locks, Electronic-based card entry systems, coupled with physical alarms. Hardware security mechanisms range from the use of computer case and cable locks as well as RFID tags for tracking computer assets. This layered approach makes it difficult for random physical security breaches to go unnoticed, but is less effective at stopping deliberate and carefully planned break-ins. Avoiding detection begins with evading building security and surveillance and methods for bypassing the electronic or physical locks which secure entry points.
CAPEC-391: Bypassing Physical Locks
An attacker uses techniques and methods to bypass physical security measures of a building or facility. Physical locks may range from traditional lock and key mechanisms, cable locks used to secure laptops or servers, locks on server cases, or other such devices. Techniques such as lock bumping, lock forcing via snap guns, or lock picking can be employed to bypass those locks and gain access to the facilities or devices they protect, although stealth, evidence of tampering, and the integrity of the lock following an attack, are considerations that may determine the method employed. Physical locks are limited by the complexity of the locking mechanism. While some locks may offer protections such as shock resistant foam to prevent bumping or lock forcing methods, many commonly employed locks offer no such countermeasures.
CAPEC-392: Lock Bumping
An attacker uses a bump key to force a lock on a building or facility and gain entry. Lock Bumping is the use of a special type of key that can be tapped or bumped to cause the pins within the lock to fall into temporary alignment, allowing the lock to be opened. Lock bumping allows an attacker to open a lock without having the correct key. A standard lock is secured by a set of internal pins that prevent the device from turning. Spring loaded driver pins push down on the key pins. When the correct key is inserted, the ridges on the key push the key pins up and against the driver pins, causing correct alignment which allows the lock cylinder to rotate. A bump key is a specially constructed key that exploits this design. When the bump key is struck or firmly tapped, its teeth transfer the force of the tap into the key pins, causing the lock to momentarily shift into proper alignment for the mechanism to be opened.
CAPEC-393: Lock Picking
An attacker uses lock picking tools and techniques to bypass the locks on a building or facility. Lock picking is the use of a special set of tools to manipulate the pins within a lock. Different sets of tools are required for each type of lock. Lock picking attacks have the advantage of being non-invasive in that if performed correctly the lock will not be damaged. A standard lock pin-and-tumbler lock is secured by a set of internal pins that prevent the tumbler device from turning. Spring loaded driver pins push down on the key pins preventing rotation so that the bolt remains in a locked position.. When the correct key is inserted, the ridges on the key push the key pins up and against the driver pins, causing correct alignment which allows the lock cylinder to rotate. Most common locks, such as domestic locks in the US, can be picked using a standard 2 tools (i.e. a torsion wrench and a hook pick).
CAPEC-394: Using a Snap Gun Lock to Force a Lock
An attacker uses a Snap Gun, also known as a Pick Gun, to force the lock on a building or facility. A Pick Gun is a special type of lock picking instrument that works on similar principles as lock bumping. A snap gun is a hand-held device with an attached metal pick. The metal pick strikes the pins within the lock, transferring motion from the key pins to the driver pins and forcing the lock into momentary alignment. A standard lock is secured by a set of internal pins that prevent the device from turning. Spring loaded driver pins push down on the key pins. When the correct key is inserted, the ridges on the key push the key pins up and against the driver pins, causing correct alignment which allows the lock cylinder to rotate. A Snap Gun exploits this design by using a metal pin to strike all of the key pins at once, forcing the driver pins to shift into an unlocked position. Unlike bump keys or lock picks, a Snap Gun may damage the lock more easily, leaving evidence that the lock has been tampered with.
CAPEC-395: Bypassing Electronic Locks and Access Controls
An attacker exploits security assumptions to bypass electronic locks or other forms of access controls. Most attacks against electronic access controls follow similar methods but utilize different tools. Some electronic locks utilize magnetic strip cards, others employ RFID tags embedded within a card or badge, or may involve more sophisticated protections such as voice-print, thumb-print, or retinal biometrics. Magnetic Strip and RFID technologies are the most widespread because they are cost effective to deploy and more easily integrated with other electronic security measures. These technologies share common weaknesses that an attacker can exploit to gain access to a facility protected by the mechanisms via copying legitimate cards or badges, or generating new cards using reverse-engineered algorithms.
CAPEC-397: Cloning Magnetic Strip Cards
An attacker duplicates the data on a Magnetic strip card (i.e. 'swipe card' or 'magstripe') to gain unauthorized access to a physical location or a person's private information. Magstripe cards encode data on a band of iron-based magnetic particles arrayed in a stripe along a rectangular card. Most magstripe card data formats conform to ISO standards 7810, 7811, 7813, 8583, and 4909. The primary advantage of magstripe technology is ease of encoding and portability, but this also renders magnetic strip cards susceptible to unauthorized duplication. If magstripe cards are used for access control, all an attacker need do is obtain a valid card long enough to make a copy of the card and then return the card to its location (i.e. a co-worker's desk). Magstripe reader/writers are widely available as well as software for analyzing data encoded on the cards. By swiping a valid card, it becomes trivial to make any number of duplicates that function as the original.
CAPEC-398: Magnetic Strip Card Brute Force Attacks
An adversary analyzes the data on two or more magnetic strip cards and is able to generate new cards containing valid sequences that allow unauthorized access and/or impersonation of individuals.
CAPEC-399: Cloning RFID Cards or Chips
An attacker analyzes data returned by an RFID chip and uses this information to duplicate a RFID signal that responds identically to the target chip. In some cases RFID chips are used for building access control, employee identification, or as markers on products being delivered along a supply chain. Some organizations also embed RFID tags inside computer assets to trigger alarms if they are removed from particular rooms, zones, or buildings. Similar to Magnetic strip cards, RFID cards are susceptible to duplication (cloning) and reuse.
CAPEC-4: Using Alternative IP Address Encodings
This attack relies on the adversary using unexpected formats for representing IP addresses. Networked applications may expect network location information in a specific format, such as fully qualified domains names (FQDNs), URL, IP address, or IP Address ranges. If the location information is not validated against a variety of different possible encodings and formats, the adversary can use an alternate format to bypass application access control.
CAPEC-40: Manipulating Writeable Terminal Devices
This attack exploits terminal devices that allow themselves to be written to by other users. The attacker sends command strings to the target terminal device hoping that the target user will hit enter and thereby execute the malicious command with their privileges. The attacker can send the results (such as copying /etc/passwd) to a known directory and collect once the attack has succeeded.
CAPEC-400: RFID Chip Deactivation or Destruction
An attacker uses methods to deactivate a passive RFID tag for the purpose of rendering the tag, badge, card, or object containing the tag unresponsive. RFID tags are used primarily for access control, inventory, or anti-theft devices. The purpose of attacking the RFID chip is to disable or damage the chip without causing damage to the object housing it.
CAPEC-401: Physically Hacking Hardware
An adversary exploits a weakness in access control to gain access to currently installed hardware and precedes to implement changes or secretly replace a hardware component which undermines the system's integrity for the purpose of carrying out an attack.
CAPEC-402: Bypassing ATA Password Security
An adversary exploits a weakness in ATA security on a drive to gain access to the information the drive contains without supplying the proper credentials. ATA Security is often employed to protect hard disk information from unauthorized access. The mechanism requires the user to type in a password before the BIOS is allowed access to drive contents. Some implementations of ATA security will accept the ATA command to update the password without the user having authenticated with the BIOS. This occurs because the security mechanism assumes the user has first authenticated via the BIOS prior to sending commands to the drive. Various methods exist for exploiting this flaw, the most common being installing the ATA protected drive into a system lacking ATA security features (a.k.a. hot swapping). Once the drive is installed into the new system the BIOS can be used to reset the drive password.
CAPEC-406: Dumpster Diving
An adversary cases an establishment and searches through trash bins, dumpsters, or areas where company information may have been accidentally discarded for information items which may be useful to the dumpster diver. The devastating nature of the items and/or information found can be anything from medical records, resumes, personal photos and emails, bank statements, account details or information about software, tech support logs and so much more, including hardware devices. By collecting this information an adversary may be able to learn important facts about the person or organization that play a role in helping the adversary in their attack.
CAPEC-407: Pretexting
An adversary engages in pretexting behavior to solicit information from target persons, or manipulate the target into performing some action that serves the adversary's interests. During a pretexting attack, the adversary creates an invented scenario, assuming an identity or role to persuade a targeted victim to release information or perform some action. It is more than just creating a lie; in some cases it can be creating a whole new identity and then using that identity to manipulate the receipt of information.
CAPEC-41: Using Meta-characters in E-mail Headers to Inject Malicious Payloads
This type of attack involves an attacker leveraging meta-characters in email headers to inject improper behavior into email programs. Email software has become increasingly sophisticated and feature-rich. In addition, email applications are ubiquitous and connected directly to the Web making them ideal targets to launch and propagate attacks. As the user demand for new functionality in email applications grows, they become more like browsers with complex rendering and plug in routines. As more email functionality is included and abstracted from the user, this creates opportunities for attackers. Virtually all email applications do not list email header information by default, however the email header contains valuable attacker vectors for the attacker to exploit particularly if the behavior of the email client application is known. Meta-characters are hidden from the user, but can contain scripts, enumerations, probes, and other attacks against the user's system.
CAPEC-410: Information Elicitation
An adversary engages an individual using any combination of social engineering methods for the purpose of extracting information. Accurate contextual and environmental queues, such as knowing important information about the target company or individual can greatly increase the success of the attack and the quality of information gathered. Authentic mimicry combined with detailed knowledge increases the success of elicitation attacks.
CAPEC-412: Pretexting via Customer Service
An adversary engages in pretexting behavior, assuming the role of someone who works for Customer Service, to solicit information from target persons, or manipulate the target into performing an action that serves the adversary's interests. One example of a scenario such as this would be to call an individual, articulate your false affiliation with a credit card company, and then attempt to get the individual to verify their credit card number.
CAPEC-413: Pretexting via Tech Support
An adversary engages in pretexting behavior, assuming the role of a tech support worker, to solicit information from target persons, or manipulate the target into performing an action that serves the adversary's interests. An adversary who uses social engineering to impersonate a tech support worker can have devastating effects on a network. This is an effective attack vector, because it can give an adversary physical access to network computers. It only takes a matter of seconds for someone to compromise a computer with physical access. One of the best technological tools at the disposal of a social engineer, posing as a technical support person, is a USB thumb drive. These are small, easy to conceal, and can be loaded with different payloads depending on what task needs to be done. However, this form of attack does not require physical access as it can also be effectively carried out via phone or email.
CAPEC-414: Pretexting via Delivery Person
An adversary engages in pretexting behavior, assuming the role of a delivery person, to solicit information from target persons, or manipulate the target into performing an action that serves the adversary's interests. Impersonating a delivery person is an effective attack and an easy attack since not much acting is involved. Usually the hardest part is looking the part and having all of the proper credentials, papers and deliveries in order to be able to pull it off.
CAPEC-415: Pretexting via Phone
An adversary engages in pretexting behavior, assuming some sort of trusted role, and contacting the targeted individual or organization via phone to solicit information from target persons, or manipulate the target into performing an action that serves the adversary's interests. This is the most common social engineering attack. Some of the most commonly effective approaches are to impersonate a fellow employee, impersonate a computer technician or to target help desk personnel.
