Patched()Fix Integer Overflow or Wraparound

[imhunterand]

Changes:

An integer overflow vulnerability exists with the length of websocket frames received via a websocket connection. An attacker would use this flaw to cause a denial of service attack on an HTTP Server allowing websocket connections. A potential denial-of-service (DoS) vector that can cause an integer overflow in the presence of malicious WebSocket frames was reported in gorilla/websocket <= v1.4.0. This could allow an attacker to consume excessive amounts of memory on the server by bypassing read limits, and potentially cause the server to go out-of-memory (OOM).

	reader        io.ReadCloser // the current reader returned to the application
	readErr       error
	br            *bufio.Reader
	readRemaining int64 // bytes remaining in current frame.
	c.readRemaining = int64(p[1] & 0x7f)

	// Send message at the limit with interleaved pong.
	w, _ := wc.NextWriter(BinaryMessage)
	w.Write(message[:readLimit-1])
	wc.WriteControl(PongMessage, []byte("this is a pong"), time.Now().Add(10*time.Second))
	w.Write(message[:1])
	w.Close()
	op, _, err := rc.NextReader()
	if op != BinaryMessage || err != nil {
		t.Fatalf("1: NextReader() returned %d, %v", op, err)
	}
	op, r, err := rc.NextReader()
	if op != BinaryMessage || err != nil {
		t.Fatalf("2: NextReader() returned %d, %v", op, err)
	}
	_, err = io.Copy(ioutil.Discard, r)
	if err != ErrReadLimit {
		t.Fatalf("io.Copy() returned %v", err)
	}

Operational Impact

CVE-2020-27813 CWE-190 CWE-400 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H