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CAPEC-46: Overflow Variables and Tags

Attack Pattern ID: 46
Abstraction: Detailed
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+ Description
This type of attack leverages the use of tags or variables from a formatted configuration data to cause buffer overflow. The adversary crafts a malicious HTML page or configuration file that includes oversized strings, thus causing an overflow.
+ Likelihood Of Attack

High

+ Typical Severity

High

+ Relationships
Section HelpThis table shows the other attack patterns and high level categories that are related to this attack pattern. These relationships are defined as ChildOf and ParentOf, and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as CanFollow, PeerOf, and CanAlsoBe are defined to show similar attack patterns that the user may want to explore.
NatureTypeIDName
ChildOfStandard Attack PatternStandard Attack Pattern - A standard level attack pattern in CAPEC is focused on a specific methodology or technique used in an attack. It is often seen as a singular piece of a fully executed attack. A standard attack pattern is meant to provide sufficient details to understand the specific technique and how it attempts to accomplish a desired goal. A standard level attack pattern is a specific type of a more abstract meta level attack pattern.100Overflow Buffers
PeerOfDetailed Attack PatternDetailed Attack Pattern - A detailed level attack pattern in CAPEC provides a low level of detail, typically leveraging a specific technique and targeting a specific technology, and expresses a complete execution flow. Detailed attack patterns are more specific than meta attack patterns and standard attack patterns and often require a specific protection mechanism to mitigate actual attacks. A detailed level attack pattern often will leverage a number of different standard level attack patterns chained together to accomplish a goal.8Buffer Overflow in an API Call
PeerOfDetailed Attack PatternDetailed Attack Pattern - A detailed level attack pattern in CAPEC provides a low level of detail, typically leveraging a specific technique and targeting a specific technology, and expresses a complete execution flow. Detailed attack patterns are more specific than meta attack patterns and standard attack patterns and often require a specific protection mechanism to mitigate actual attacks. A detailed level attack pattern often will leverage a number of different standard level attack patterns chained together to accomplish a goal.10Buffer Overflow via Environment Variables
Section HelpThis table shows the views that this attack pattern belongs to and top level categories within that view.
+ Execution Flow
Explore
  1. Identify target application: The adversary identifies a target application or program to perform the buffer overflow on. Adversaries look for applications or programs that accept formatted files, such as configuration files, as input.

Experiment
  1. Find injection vector: The adversary identifies an injection vector to deliver the excessive content to the targeted application's buffer.

    Techniques
    Knowing the type of file that an application takes as input, the adversary takes a normal input file and modifies a single variable or tag to contain a large amount of data. If there is a crash, this means that a buffer overflow attack is possible. The adversary will keep changing single variables or tags one by one until they see a change in behavior.
  2. Craft overflow content: The adversary crafts the content to be injected. If the intent is to simply cause the software to crash, the content need only consist of an excessive quantity of random data. If the intent is to leverage the overflow for execution of arbitrary code, the adversary crafts the payload in such a way that the overwritten return address is replaced with one of the adversary's choosing.

    Techniques
    Create malicious shellcode that will execute when the program execution is returned to it.
    Use a NOP-sled in the overflow content to more easily "slide" into the malicious code. This is done so that the exact return address need not be correct, only in the range of all of the NOPs
Exploit
  1. Overflow the buffer: The adversary will upload the crafted file to the application, causing a buffer overflow.

+ Prerequisites
The target program consumes user-controllable data in the form of tags or variables.
The target program does not perform sufficient boundary checking.
+ Skills Required
[Level: Low]
An adversary can simply overflow a buffer by inserting a long string into an adversary-modifiable injection vector. The result can be a DoS.
[Level: High]
Exploiting a buffer overflow to inject malicious code into the stack of a software system or even the heap can require a higher skill level.
+ Consequences
Section HelpThis table specifies different individual consequences associated with the attack pattern. The Scope identifies the security property that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in their attack. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a pattern will be used to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.
ScopeImpactLikelihood
Availability
Unreliable Execution
Confidentiality
Integrity
Availability
Execute Unauthorized Commands
Confidentiality
Read Data
Integrity
Modify Data
+ Mitigations
Use a language or compiler that performs automatic bounds checking.
Use an abstraction library to abstract away risky APIs. Not a complete solution.
Compiler-based canary mechanisms such as StackGuard, ProPolice and the Microsoft Visual Studio /GS flag. Unless this provides automatic bounds checking, it is not a complete solution.
Use OS-level preventative functionality. Not a complete solution.
Do not trust input data from user. Validate all user input.
+ Example Instances

A buffer overflow vulnerability exists in the Yamaha MidiPlug that can be accessed via a Text variable found in an EMBED tag.

See also: CVE-1999-0946

A buffer overflow in Exim allows local users to gain root privileges by providing a long :include: option in a .forward file.

See also: CVE-1999-0971
+ References
[REF-1] G. Hoglund and G. McGraw. "Exploiting Software: How to Break Code". Addison-Wesley. 2004-02.
+ Content History
Submissions
Submission DateSubmitterOrganization
2014-06-23
(Version 2.6)
CAPEC Content TeamThe MITRE Corporation
Modifications
Modification DateModifierOrganization
2018-07-31
(Version 2.12)
CAPEC Content TeamThe MITRE Corporation
Updated References
2020-07-30
(Version 3.3)
CAPEC Content TeamThe MITRE Corporation
Updated Execution_Flow
2021-10-21
(Version 3.6)
CAPEC Content TeamThe MITRE Corporation
Updated Execution_Flow
2022-02-22
(Version 3.7)
CAPEC Content TeamThe MITRE Corporation
Updated Description, Skills_Required
2022-09-29
(Version 3.8)
CAPEC Content TeamThe MITRE Corporation
Updated Example_Instances
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Page Last Updated or Reviewed: July 31, 2018