CWE-692: Incomplete Denylist to Cross-Site Scripting
The product uses a denylist-based protection mechanism to defend against XSS attacks, but the denylist is incomplete, allowing XSS variants to succeed.
How it's found
Incomplete Denylist to Cross-Site Scripting only appears when several contributing weaknesses combine. Testers look for each contributing condition separately, then chain them together to confirm the combined weakness is actually reachable and exploitable.
While XSS might seem simple to prevent, web browsers vary so widely in how they parse web pages, that a denylist cannot keep track of all the variations. The "XSS Cheat Sheet" [REF-714] contains a large number of attacks that are intended to bypass incomplete denylists.
Consequences
- Execute Unauthorized Code or Commands
Where this fits in a TurboPentest engagement
TurboPentest's agentic pentest is powerful and covers a broad range of issues automatically. This particular class is best confirmed in a manual IntegSec engagement, where human pentesters apply deeper methodology and a larger context window than any automated pass.
Frequently asked questions
What is CWE-692?
The product uses a denylist-based protection mechanism to defend against XSS attacks, but the denylist is incomplete, allowing XSS variants to succeed.
How do you find Incomplete Denylist to Cross-Site Scripting?
Incomplete Denylist to Cross-Site Scripting only appears when several contributing weaknesses combine. Testers look for each contributing condition separately, then chain them together to confirm the combined weakness is actually reachable and exploitable.
What is the impact of CWE-692?
Execute Unauthorized Code or Commands
Does TurboPentest test for Incomplete Denylist to Cross-Site Scripting?
TurboPentest's agentic pentest is powerful and covers a broad range of issues automatically. This particular class is best confirmed in a manual IntegSec engagement, where human pentesters apply deeper methodology and a larger context window than any automated pass.
Related CWEs
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