| Name |
HTTP Parameter Pollution (HPP) |
|
| Likelyhood of attack |
Typical severity |
| High |
Medium |
|
| Summary |
An attacker overrides or adds HTTP GET/POST parameters by injecting query string delimiters. Via HPP it may be possible to override existing hardcoded HTTP parameters, modify the application behaviors, access and, potentially exploit, uncontrollable variables, and bypass input validation checkpoints and WAF rules. |
| Prerequisites |
HTTP protocol is used with some GET/POST parameters passed |
| Solutions | Configuration: If using a Web Application Firewall (WAF), filters should be carefully configured to detect abnormal HTTP requests Design: Perform URL encoding Implementation: Use strict regular expressions in URL rewriting Implementation: Beware of multiple occurrences of a parameter in a Query String |
| Related Weaknesses |
|
CWE ID
|
Description
|
| CWE-88 |
Improper Neutralization of Argument Delimiters in a Command ('Argument Injection') |
| CWE-147 |
Improper Neutralization of Input Terminators |
| CWE-235 |
Improper Handling of Extra Parameters |
|
| Related CAPECS |
|
CAPEC ID
|
Description
|
| CAPEC-15 |
An attack of this type exploits a programs' vulnerabilities that allows an attacker's commands to be concatenated onto a legitimate command with the intent of targeting other resources such as the file system or database. The system that uses a filter or denylist input validation, as opposed to allowlist validation is vulnerable to an attacker who predicts delimiters (or combinations of delimiters) not present in the filter or denylist. As with other injection attacks, the attacker uses the command delimiter payload as an entry point to tunnel through the application and activate additional attacks through SQL queries, shell commands, network scanning, and so on. |
|
| Taxonomy: OWASP Attacks |
|
Entry ID
|
Entry Name
|
| Link |
Web Parameter Tampering |
|