"The resources required to find flaws is lower than those required to fix any found flaws."
I really think you're underestimating the effort that goes into vulnerability hunting. It's true you *can* stumble across an issue, or run an automated tool that spits out reams of false positives or garbage inputs that trigger crashes for unknown reasons, and you can submit low-quality bug reports based on that. That's clearly not what Joshua has done here or what most security researchers do. The reports are high quality, they explain the logic and broad conditionality leading to the issue and identify the code that's broken. The research is impressively exhaustive. I don't know Squid (or care much about it to be honest) but most of the issues look like their security consequences could at least be mitigated with very small patches, even if a 'proper' fix would require wider new features to handle the failure cases in ideal ways. Of course it's a daunting task to write even 55 small patches for an old code base, but that's a reflection of the effort that went into finding the issues. It's not because Joshua was too lazy to do the hard bit and solve them. Finding them *is* a big step toward solving them.
Sometimes vulnerability reports are met with outright hostility, which is depressing, but sometimes the response is reminiscent of your comment. There's this kind of polite 'we want to be seen to say we appreciate your bug report but secretly we'd rather you left alone' which is ultimately still a veiled appeal to security through obscurity.