From 709fda0a42b8ffde78136af52e02f260622926fa Mon Sep 17 00:00:00 2001
From: Neal Patel <nealpatel@google.com>
Date: Wed, 21 May 2025 14:11:44 -0400
Subject: [PATCH] net/http: strip sensitive proxy headers from redirect
 requests

Similarly to Authentication entries, Proxy-Authentication entries should be stripped to ensure sensitive information is not leaked on redirects outside of the original domain.

https://fetch.spec.whatwg.org/#authentication-entries

Thanks to Takeshi Kaneko (GMO Cybersecurity by Ierae, Inc.) for reporting this issue.

Updates golang/go#73816
Fixes golang/go#73905
Fixes CVE-2025-4673

Confict: no
Reference:https://go-review.googlesource.com/c/go/+/679255

Change-Id: I1615f31977a2fd014fbc12aae43f82692315a6d0
Reviewed-on: https://go-review.googlesource.com/c/go/+/679255
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Signed-off-by: jichao wu <wujichao1@huawei.com>
---
 src/net/http/client.go      | 3 ++-
 src/net/http/client_test.go | 3 +++
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/net/http/client.go b/src/net/http/client.go
index 9231f63..a814cf3 100644
--- a/src/net/http/client.go
+++ b/src/net/http/client.go
@@ -805,7 +805,8 @@ func (c *Client) makeHeadersCopier(ireq *Request) func(req *Request, stripSensit
 		for k, vv := range ireqhdr {
 			sensitive := false
 			switch CanonicalHeaderKey(k) {
-			case "Authorization", "Www-Authenticate", "Cookie", "Cookie2":
+			case "Authorization", "Www-Authenticate", "Cookie", "Cookie2",
+				"Proxy-Authorization", "Proxy-Authenticate":
 				sensitive = true
 			}
 			if !(sensitive && stripSensitiveHeaders) {
diff --git a/src/net/http/client_test.go b/src/net/http/client_test.go
index 1ce9539..8ab4f58 100644
--- a/src/net/http/client_test.go
+++ b/src/net/http/client_test.go
@@ -1547,6 +1547,8 @@ func testClientStripHeadersOnRepeatedRedirect(t *testing.T, mode testMode) {
 		if r.Host+r.URL.Path != "a.example.com/" {
 			if h := r.Header.Get("Authorization"); h != "" {
 				t.Errorf("on request to %v%v, Authorization=%q, want no header", r.Host, r.URL.Path, h)
+			} else if h := r.Header.Get("Proxy-Authorization"); h != "" {
+				t.Errorf("on request to %v%v, Proxy-Authorization=%q, want no header", r.Host, r.URL.Path, h)
 			}
 		}
 		// Follow a chain of redirects from a to b and back to a.
@@ -1575,6 +1577,7 @@ func testClientStripHeadersOnRepeatedRedirect(t *testing.T, mode testMode) {
 	req, _ := NewRequest("GET", proto+"://a.example.com/", nil)
 	req.Header.Add("Cookie", "foo=bar")
 	req.Header.Add("Authorization", "secretpassword")
+	req.Header.Add("Proxy-Authorization", "secretpassword")
 	res, err := c.Do(req)
 	if err != nil {
 		t.Fatal(err)
-- 
2.33.0