Mô tả CAPEC

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.

Thông tin CAPEC

Luồng thực thi

1) Explore

[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.

2) Experiment

[Find injection vector] The adversary identifies an injection vector to deliver the excessive content to the targeted application's buffer.

Kỹ thuật

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.

3) Experiment

[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.

Kỹ thuật

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

4) Exploit

[Overflow the buffer] The adversary will upload the crafted file to the application, causing a buffer overflow.

Điều kiện tiên quyết

The target program consumes user-controllable data in the form of tags or variables.
The target program does not perform sufficient boundary checking.

Kỹ năng cần thiết

An adversary can simply overflow a buffer by inserting a long string into an adversary-modifiable injection vector. The result can be a DoS.
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.

Các biện pháp giảm thiểu

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.

Điểm yếu liên quan

CWE-ID	Tên điểm yếu
CWE-120	Buffer Copy without Checking Size of Input The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer.
CWE-118	Incorrect Access of Indexable Resource The product does not restrict or incorrectly restricts operations within the boundaries of a resource that is accessed using an index or pointer, such as memory or files.
CWE-119	Improper Restriction of Operations within the Bounds of a Memory Buffer The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary.
CWE-74	Improper Neutralization of Special Elements in Output Used by a Downstream Component The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.
CWE-20	Improper Input Validation The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
CWE-680	Integer Overflow to Buffer Overflow The product performs a calculation to determine how much memory to allocate, but an integer overflow can occur that causes less memory to be allocated than expected, leading to a buffer overflow.
CWE-733	Compiler Optimization Removal or Modification of Security-critical Code The developer builds a security-critical protection mechanism into the software, but the compiler optimizes the program such that the mechanism is removed or modified.
CWE-697	Incorrect Comparison The product compares two entities in a security-relevant context, but the comparison is incorrect.

Tài liệu tham khảo

REF-1

Exploiting Software: How to Break Code
G. Hoglund, G. McGraw.

Gửi

Tên	Tổ chức	Ngày	Ngày phát hành
CAPEC Content Team	The MITRE Corporation	2014-06-23 +00:00

Sửa đổi

Tên	Tổ chức	Ngày	Bình luận
CAPEC Content Team	The MITRE Corporation	2018-07-31 +00:00	Updated References
CAPEC Content Team	The MITRE Corporation	2020-07-30 +00:00	Updated Execution_Flow
CAPEC Content Team	The MITRE Corporation	2021-10-21 +00:00	Updated Execution_Flow
CAPEC Content Team	The MITRE Corporation	2022-02-22 +00:00	Updated Description, Skills_Required
CAPEC Content Team	The MITRE Corporation	2022-09-29 +00:00	Updated Example_Instances

Chi tiết CAPEC-46

CAPEC-46