CAPEC-492
Regular Expression Exponential Blowup
2014-06-23
00h00 +00:00
00h00 +00:00
指定 CAPEC 提醒
随时了解指定 CAPEC 的变更。
CAPEC 描述
An adversary may execute an attack on a program that uses a poor Regular Expression(Regex) implementation by choosing input that results in an extreme situation for the Regex. A typical extreme situation operates at exponential time compared to the input size. This is due to most implementations using a Nondeterministic Finite Automaton(NFA) state machine to be built by the Regex algorithm since NFA allows backtracking and thus more complex regular expressions.
CAPEC 信息
前提条件
This type of an attack requires the ability to identify hosts running a poorly implemented Regex, and the ability to send crafted input to exploit the regular expression.缓解措施
Test custom written Regex with fuzzing to determine if the Regex is a poor one. Add timeouts to processes that handle the Regex logic. If an evil Regex is found rewrite it as a good Regex.相关弱点
| 弱点名称 | |
|---|---|
CWE-400 |
Uncontrolled Resource Consumption The product does not properly control the allocation and maintenance of a limited resource. |
CWE-1333 |
Inefficient Regular Expression Complexity The product uses a regular expression with a worst-case computational complexity that is inefficient and possibly exponential. |
参考资料
REF-421
Regular Expression Denial of Service Attacks and DefensesBryan Sullivan.
http://msdn.microsoft.com/en-au/magazine/ff646973.aspx
提交记录
| 名称 | 组织 | 日期 | 发布日期 |
|---|---|---|---|
| CAPEC Content Team | The MITRE Corporation |
修改记录
| 名称 | 组织 | 日期 | 备注 |
|---|---|---|---|
| CAPEC Content Team | The MITRE Corporation | Updated Related_Weaknesses | |
| CAPEC Content Team | The MITRE Corporation | Updated Related_Attack_Patterns | |
| 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, Extended_Description |
