Arbitrary code execution via exec() in response_conditions_matched

Summary
response_conditions_matched() in nettacker/core/lib/http.py evaluates the responsetime condition using exec() with an operator taken directly from module YAML.

This allows arbitrary Python execution if a crafted module provides a malicious condition string.

Location:
nettacker/core/lib/http.py
~line 95
Vulnerable pattern
exec(
f"matched = response['responsetime'] "
f"{conditions['responsetime'].split()[0]} "
f"{conditions['responsetime'].split()[1]}"
)

Since the operator comes from YAML, a condition like:

conditions:
responsetime: ">= 0 or import('os').system('id')"

would execute arbitrary code during scan.

Fix

Replace exec() with explicit operator dispatch:

ops = {
'==': float.eq,
'!=': float.ne,
'>=': float.ge,
'<=': float.le,
'>': float.gt,
'<': float.lt,
}

Start in nettacker/core/lib/http.py around response_conditions_matched() and inspect how the responsetime condition is parsed. Verify the supported comparison operators and ensure crafted module YAML cannot execute arbitrary Python while valid comparisons still work. Done means the dynamic exec() path is removed and the condition behavior remains covered by verification of safe and malicious inputs.