CAPEC-52
Embedding NULL Bytes
2014-06-23
00h00 +00:00
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Mô tả CAPEC
An adversary embeds one or more null bytes in input to the target software. This attack relies on the usage of a null-valued byte as a string terminator in many environments. The goal is for certain components of the target software to stop processing the input when it encounters the null byte(s).
Thông tin CAPEC
Luồng thực thi
1) Explore
[Survey the application for user-controllable inputs] Using a browser, an automated tool or by inspecting the application, an adversary records all entry points to the application.
Kỹ thuật
- Use a spidering tool to follow and record all links and analyze the web pages to find entry points. Make special note of any links that include parameters in the URL.
- Use a proxy tool to record all user input entry points visited during a manual traversal of the web application.
- Use a browser to manually explore the website and analyze how it is constructed. Many browsers' plugins are available to facilitate the analysis or automate the discovery.
- Manually inspect the application to find entry points.
2) Experiment
[Probe entry points to locate vulnerabilities] The adversary uses the entry points gathered in the "Explore" phase as a target list and injects postfix null byte(s) to observe how the application handles them as input. The adversary is looking for areas where user input is placed in the middle of a string, and the null byte causes the application to stop processing the string at the end of the user input.
Kỹ thuật
- Try different encodings for null such as \0 or %00
3) Exploit
[Remove data after null byte(s)] After determined entry points that are vulnerable, the adversary places a null byte(s) such that they remove data after the null byte(s) in a way that is beneficial to them.
Kỹ thuật
- If the input is a directory as part of a longer file path, add a null byte(s) at the end of the input to try to traverse to the given directory.
Điều kiện tiên quyết
The program does not properly handle postfix NULL terminatorsKỹ năng cần thiết
Directory traversalExecution of arbitrary code
Các biện pháp giảm thiểu
Properly handle the NULL characters supplied as part of user input prior to doing anything with the data.Điểm yếu liên quan
| Tên điểm yếu | |
|---|---|
CWE-158 |
Improper Neutralization of Null Byte or NUL Character The product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes NUL characters or null bytes when they are sent to a downstream component. |
CWE-172 |
Improper Encoding or Decoding of Data The product does not properly encode or decode data, resulting in unexpected values that are not equivalent to the original data. |
CWE-173 |
Improper Handling of Alternate Encoding The product does not properly handle when an input uses an alternate encoding that is valid for the control sphere to which the input is being sent. |
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-697 |
Incorrect Comparison The product compares two entities in a security-relevant context, but the comparison is incorrect. |
CWE-707 |
Improper Neutralization The product does not ensure or incorrectly ensures that structured messages or data are well-formed and that certain security properties are met before being used when received from an upstream component, or before being sent to a downstream component. |
Tài liệu tham khảo
REF-1
Exploiting Software: How to Break CodeG. Hoglund, G. McGraw.
REF-445
Adobe Acrobat/Acrobat Reader ActiveX Control Buffer Overflow Vulnerabilityhttp://labs.idefense.com/intelligence/vulnerabilities/display.php?id=126
REF-446
PHP Input Validation Vulnerabilitieshttp://msgs.securepoint.com/bugtraq/
Gửi
| Tên | Tổ chức | Ngày | Ngày phát hành |
|---|---|---|---|
| CAPEC Content Team | The MITRE Corporation |
Sửa đổi
| Tên | Tổ chức | Ngày | Bình luận |
|---|---|---|---|
| CAPEC Content Team | The MITRE Corporation | Updated Related_Attack_Patterns | |
| CAPEC Content Team | The MITRE Corporation | Updated Example_Instances | |
| CAPEC Content Team | The MITRE Corporation | Updated Taxonomy_Mappings | |
| CAPEC Content Team | The MITRE Corporation | Updated Related_Weaknesses | |
| CAPEC Content Team | The MITRE Corporation | Updated Description, Example_Instances, Execution_Flow | |
| CAPEC Content Team | The MITRE Corporation | Updated Example_Instances |
