CWE-440: Expected Behavior Violation
A feature, API, or function does not perform according to its specification.
How it's found
Expected Behavior Violation is typically found by tracing untrusted input from where it enters the system to the point where it is used without the check or neutralization this weakness describes, combining manual code review with dynamic testing.
Vulnerable vs. safe
mie_d = (mie_q & ~mideleg_q) | (csr_wdata & mideleg_q) | utval_q;// the mideleg makes sure only delegate-able register//(and therefore also only implemented registers) are writtenriscv::CSR_SIE: beginend...unique case (csr_addr.address)...endcaseif (csr_we) beginendmodule csr_regfile #(...)(...);...// ---------------------------// CSR Write and update logic// ---------------------------...endmodulemie_d = (mie_q & ~mideleg_q) | (csr_wdata & mideleg_q);// the mideleg makes sure only delegate-able register//(and therefore also only implemented registers) are writtenriscv::CSR_SIE: beginend...unique case (csr_addr.address)...endcaseif (csr_we) beginendmodule csr_regfile #(...)(...);...// ---------------------------// CSR Write and update logic// ---------------------------...endmoduleConsequences
- Quality Degradation, Varies by Context
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-440?
A feature, API, or function does not perform according to its specification.
How do you find Expected Behavior Violation?
Expected Behavior Violation is typically found by tracing untrusted input from where it enters the system to the point where it is used without the check or neutralization this weakness describes, combining manual code review with dynamic testing.
What is the impact of CWE-440?
Quality Degradation, Varies by Context
Does TurboPentest test for Expected Behavior Violation?
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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