| Name |
Overflow Buffers |
|
| Likelyhood of attack |
Typical severity |
| High |
Very High |
|
| Summary |
Buffer Overflow attacks target improper or missing bounds checking on buffer operations, typically triggered by input injected by an adversary. As a consequence, an adversary is able to write past the boundaries of allocated buffer regions in memory, causing a program crash or potentially redirection of execution as per the adversaries' choice. |
| Prerequisites |
Targeted software performs buffer operations. Targeted software inadequately performs bounds-checking on buffer operations. Adversary has the capability to influence the input to buffer operations. |
| Execution Flow |
| Step |
Phase |
Description |
Techniques |
| 1 |
Explore |
The adversary identifies a buffer to target. Buffer regions are either allotted on the stack or the heap, and the exact nature of attack would vary depending on the location of the buffer |
|
| 2 |
Explore |
Next, the adversary identifies an injection vector to deliver the excessive content to the targeted buffer. |
|
| 3 |
Experiment |
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 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. |
|
| 4 |
Exploit |
The adversary injects the content into the targeted software. |
|
| 5 |
Exploit |
Upon successful exploitation, the system either crashes or control of the program is returned to a location of the adversaries' choice. This can result in execution of arbitrary code or escalated privileges, depending upon the exploited target. |
|
|
| Solutions | 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. Utilize static source code analysis tools to identify potential buffer overflow weaknesses in the software. |
| Related Weaknesses |
|
CWE ID
|
Description
|
| CWE-19 |
Data Processing Errors |
| CWE-119 |
Improper Restriction of Operations within the Bounds of a Memory Buffer |
| CWE-120 |
Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') |
| CWE-129 |
Improper Validation of Array Index |
| CWE-131 |
Incorrect Calculation of Buffer Size |
| CWE-680 |
Integer Overflow to Buffer Overflow |
| CWE-805 |
Buffer Access with Incorrect Length Value |
|
| Related CAPECS |
|
CAPEC ID
|
Description
|
| CAPEC-123 |
An adversary manipulates an application's interaction with a buffer in an attempt to read or modify data they shouldn't have access to. Buffer attacks are distinguished in that it is the buffer space itself that is the target of the attack rather than any code responsible for interpreting the content of the buffer. In virtually all buffer attacks the content that is placed in the buffer is immaterial. Instead, most buffer attacks involve retrieving or providing more input than can be stored in the allocated buffer, resulting in the reading or overwriting of other unintended program memory. |
|
| Taxonomy: WASC |
|
Entry ID
|
Entry Name
|
| 07 |
Buffer Overflow |
|
| Taxonomy: OWASP Attacks |
|
Entry ID
|
Entry Name
|
| Link |
Buffer overflow attack |
|