File CVE-2016-5386.patch of Package go1.4

diff --git a/src/net/http/cgi/host.go b/src/net/http/cgi/host.go
index ec95a97..a851285 100644
--- a/src/net/http/cgi/host.go
+++ b/src/net/http/cgi/host.go
@@ -139,6 +139,10 @@ func (h *Handler) ServeHTTP(rw http.ResponseWriter, req *http.Request) {

 	for k, v := range req.Header {
 		k = strings.Map(upperCaseAndUnderscore, k)
+		if k == "PROXY" {
+			// See Issue 16405
+			continue
+		}
 		joinStr := ", "
 		if k == "COOKIE" {
 			joinStr = "; "
diff --git a/src/net/http/cgi/host_test.go b/src/net/http/cgi/host_test.go
index 8c16e68..84b62ba 100644
--- a/src/net/http/cgi/host_test.go
+++ b/src/net/http/cgi/host_test.go
@@ -90,6 +90,9 @@ func check(t *testing.T) {
 		// TODO: make the child process be Go, not Perl.
 		t.Skip("Skipping test: test.cgi failed.")
 	}
+	for _, check := range checks {
+		check(m)
+	}
 }

 func TestCGIBasicGet(t *testing.T) {
@@ -197,6 +200,31 @@ func TestDupHeaders(t *testing.T) {
 		expectedMap)
 }

+// Issue 16405: CGI+http.Transport differing uses of HTTP_PROXY.
+// Verify we don't set the HTTP_PROXY environment variable.
+// Hope nobody was depending on it. It's not a known header, though.
+func TestDropProxyHeader(t *testing.T) {
+	check(t)
+	h := &Handler{
+		Path: "testdata/test.cgi",
+	}
+	expectedMap := map[string]string{
+		"env-REQUEST_URI":     "/myscript/bar?a=b",
+		"env-SCRIPT_FILENAME": "testdata/test.cgi",
+		"env-HTTP_X_FOO":      "a",
+	}
+	runCgiTest(t, h, "GET /myscript/bar?a=b HTTP/1.0\n"+
+		"X-Foo: a\n"+
+		"Proxy: should_be_stripped\n"+
+		"Host: example.com\n\n",
+		expectedMap,
+		func(reqInfo map[string]string) {
+			if v, ok := reqInfo["env-HTTP_PROXY"]; ok {
+				t.Errorf("HTTP_PROXY = %q; should be absent", v)
+			}
+		})
+}
+
 func TestPathInfoNoRoot(t *testing.T) {
 	check(t)
 	h := &Handler{
diff --git a/src/net/http/transport.go b/src/net/http/transport.go
index 782f7cd..424dd8c 100644
--- a/src/net/http/transport.go
+++ b/src/net/http/transport.go
@@ -140,6 +140,9 @@ func ProxyFromEnvironment(req *Request) (*url.URL, error) {
 	}
 	if proxy == "" {
 		proxy = httpProxyEnv.Get()
+		if proxy != "" && os.Getenv("REQUEST_METHOD") != "" {
+			return nil, errors.New("net/http: refusing to use HTTP_PROXY value in CGI environment; see golang.org/s/cgihttpproxy")
+		}
 	}
 	if proxy == "" {
 		return nil, nil
diff --git a/src/net/http/transport_test.go b/src/net/http/transport_test.go
index defa633..760fc8e 100644
--- a/src/net/http/transport_test.go
+++ b/src/net/http/transport_test.go
@@ -1705,7 +1705,8 @@ type proxyFromEnvTest struct {

 	env      string // HTTP_PROXY
 	httpsenv string // HTTPS_PROXY
-	noenv    string // NO_RPXY
+	noenv    string // NO_PROXY
+	reqmeth  string // REQUEST_METHOD

 	want    string
 	wanterr error
@@ -1729,6 +1730,10 @@ func (t proxyFromEnvTest) String() string {
 		space()
 		fmt.Fprintf(&buf, "no_proxy=%q", t.noenv)
 	}
+	if t.reqmeth != "" {
+		space()
+		fmt.Fprintf(&buf, "request_method=%q", t.reqmeth)
+	}
 	req := "http://example.com"
 	if t.req != "" {
 		req = t.req
@@ -1752,6 +1757,12 @@ var proxyFromEnvTests = []proxyFromEnvTest{
 	{req: "https://secure.tld/", env: "http.proxy.tld", httpsenv: "secure.proxy.tld", want: "http://secure.proxy.tld"},
 	{req: "https://secure.tld/", env: "http.proxy.tld", httpsenv: "https://secure.proxy.tld", want: "https://secure.proxy.tld"},

+	// Issue 16405: don't use HTTP_PROXY in a CGI environment,
+	// where HTTP_PROXY can be attacker-controlled.
+	{env: "http://10.1.2.3:8080", reqmeth: "POST",
+		want:    "<nil>",
+		wanterr: errors.New("net/http: refusing to use HTTP_PROXY value in CGI environment; see golang.org/s/cgihttpproxy")},
+
 	{want: "<nil>"},

 	{noenv: "example.com", req: "http://example.com/", env: "proxy", want: "<nil>"},
@@ -1767,6 +1778,7 @@ func TestProxyFromEnvironment(t *testing.T) {
 		os.Setenv("HTTP_PROXY", tt.env)
 		os.Setenv("HTTPS_PROXY", tt.httpsenv)
 		os.Setenv("NO_PROXY", tt.noenv)
+		os.Setenv("REQUEST_METHOD", tt.reqmeth)
 		ResetCachedEnvironment()
 		reqURL := tt.req
 		if reqURL == "" {