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CAPEC-8: Buffer Overflow in an API Call

Attack Pattern ID: 8
Abstraction: Detailed
Presentation Filter:
+ Description
This attack targets libraries or shared code modules which are vulnerable to buffer overflow attacks. An adversary who has knowledge of known vulnerable libraries or shared code can easily target software that makes use of these libraries. All clients that make use of the code library thus become vulnerable by association. This has a very broad effect on security across a system, usually affecting more than one software process.
+ 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.46Overflow Variables and Tags
CanFollowStandard 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.69Target Programs with Elevated Privileges
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, with knowledge of vulnerable libraries or shared code modules, identifies a target application or program that makes use of these.

Experiment
  1. Find injection vector: The adversary attempts to use the API, and if they can they send a large amount of data to see if the buffer overflow attack really does work.

    Techniques
    Provide large input to a program or application and observe the behavior. If there is a crash, this means that a buffer overflow attack is possible.
  2. Craft overflow content: The adversary crafts the content to be injected based on their knowledge of the vulnerability and their desired outcome. 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 will craft a set of content that not only overflows the targeted buffer but does so in such a way that the overwritten return address is replaced with one of the adversaries' choosing which points to code injected by the adversary.

    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: Using the API as the injection vector, the adversary injects the crafted overflow content into the buffer.

+ Prerequisites
The target host exposes an API to the user.
One or more API functions exposed by the target host has a buffer overflow vulnerability.
+ 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 secure functions not vulnerable to buffer overflow.
If you have to use dangerous functions, make sure that you do boundary checking.
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.
+ Example Instances
Attack Example: Libc in FreeBSD

A buffer overflow in the FreeBSD utility setlocale (found in the libc module) puts many programs at risk all at once.

Xtlib

A buffer overflow in the Xt library of the X windowing system allows local users to execute commands with root privileges.

+ 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
2021-10-21
(Version 3.6)
CAPEC Content TeamThe MITRE Corporation
Updated Description, Execution_Flow
2022-02-22
(Version 3.7)
CAPEC Content TeamThe MITRE Corporation
Updated 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: October 21, 2021