Security context

Highlights

Arbitrary File Write: 2 prior fixes. Scrutinize any change in this area.

src/Compress/Zip.php: most-fixed (1 issue). Treat as high-risk during review.

3 high-severity fixes in this history; regressions here are high-impact.

Recurring patterns

Arbitrary File Write: The original filter allowed moving arbitrary files via rename(), enabling an attacker to write to any writable location by supplying a crafted source path. The fix removed the fallback and now requires is_uploaded_file().

Arbitrary File Write: A generic rename-based upload filter could move non-uploaded files, leading to arbitrary file write. The fix introduced a dedicated filter using move_uploaded_file(), which only operates on actual uploads.

Path Traversal: ZIP extraction used extractTo() without validating entry names, allowing malicious archives to write outside the target directory via upward traversal. The fix adds target directory validation and traversal detection.