| Name | Filter Failure through Buffer Overflow |
| Summary | In this attack, the idea is to cause an active filter to fail by causing an oversized transaction. An attacker may try to feed overly long input strings to the program in an attempt to overwhelm the filter (by causing a buffer overflow) and hoping that the filter does not fail securely (i.e. the user input is let into the system unfiltered). |
| Prerequisites | Ability to control the length of data passed to an active filter. |
| Solutions | Make sure that ANY failure occurring in the filtering or input validation routine is properly handled and that offending input is NOT allowed to go through. Basically make sure that the vault is closed when failure occurs.
Pre-design: Use a language or compiler that performs automatic bounds checking.
Pre-design through Build: 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.
Operational: Use OS-level preventative functionality. Not a complete solution.
Design: Use an abstraction library to abstract away risky APIs. Not a complete solution. |
| Related Weaknesses |
| CWE ID | Description |
| CWE-20 | Improper Input Validation |
| CWE-74 | Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection') |
| CWE-118 | Incorrect Access of Indexable Resource ('Range Error') |
| 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-680 | Integer Overflow to Buffer Overflow |
| CWE-697 | Incorrect Comparison |
| CWE-733 | Compiler Optimization Removal or Modification of Security-critical Code |
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