From 20586c0dbe03d144f914155f879fa5ee287591a1 Mon Sep 17 00:00:00 2001 From: Damien Neil Date: Thu, 11 Jan 2024 11:31:57 -0800 Subject: [PATCH] [release-branch.go1.21] net/http, net/http/cookiejar: avoid subdomain matches on IPv6 zones When deciding whether to forward cookies or sensitive headers across a redirect, do not attempt to interpret an IPv6 address as a domain name. Avoids a case where a maliciously-crafted redirect to an IPv6 address with a scoped addressing zone could be misinterpreted as a within-domain redirect. For example, we could interpret "::1%.www.example.com" as a subdomain of "www.example.com". Thanks to Juho Nurminen of Mattermost for reporting this issue. Fixes CVE-2023-45289 Fixes #65385 For #65065 Change-Id: I8f463f59f0e700c8a18733d2b264a8bcb3a19599 Reviewed-on: https://team-review.git.corp.google.com/c/golang/go-private/+/2131938 Reviewed-by: Tatiana Bradley Reviewed-by: Roland Shoemaker Reviewed-on: https://team-review.git.corp.google.com/c/golang/go-private/+/2173775 Reviewed-by: Carlos Amedee Reviewed-on: https://go-review.googlesource.com/c/go/+/569239 Reviewed-by: Carlos Amedee Auto-Submit: Michael Knyszek TryBot-Bypass: Michael Knyszek Upstream-Status: Backport [https://github.com/golang/go/commit/20586c0dbe03d144f914155f879fa5ee287591a1] CVE: CVE-2023-45289 Signed-off-by: Vijay Anusuri --- src/net/http/client.go | 6 ++++++ src/net/http/client_test.go | 1 + src/net/http/cookiejar/jar.go | 7 +++++++ src/net/http/cookiejar/jar_test.go | 10 ++++++++++ 4 files changed, 24 insertions(+) diff --git a/src/net/http/client.go b/src/net/http/client.go index a496f1c..2031834 100644 --- a/src/net/http/client.go +++ b/src/net/http/client.go @@ -973,6 +973,12 @@ func isDomainOrSubdomain(sub, parent string) bool { if sub == parent { return true } + // If sub contains a :, it's probably an IPv6 address (and is definitely not a hostname). + // Don't check the suffix in this case, to avoid matching the contents of a IPv6 zone. + // For example, "::1%.www.example.com" is not a subdomain of "www.example.com". + if strings.ContainsAny(sub, ":%") { + return false + } // If sub is "foo.example.com" and parent is "example.com", // that means sub must end in "."+parent. // Do it without allocating. diff --git a/src/net/http/client_test.go b/src/net/http/client_test.go index 2b4f53f..442fe35 100644 --- a/src/net/http/client_test.go +++ b/src/net/http/client_test.go @@ -1703,6 +1703,7 @@ func TestShouldCopyHeaderOnRedirect(t *testing.T) { {"cookie2", "http://foo.com/", "http://bar.com/", false}, {"authorization", "http://foo.com/", "http://bar.com/", false}, {"www-authenticate", "http://foo.com/", "http://bar.com/", false}, + {"authorization", "http://foo.com/", "http://[::1%25.foo.com]/", false}, // But subdomains should work: {"www-authenticate", "http://foo.com/", "http://foo.com/", true}, diff --git a/src/net/http/cookiejar/jar.go b/src/net/http/cookiejar/jar.go index 9f19917..18cbfc2 100644 --- a/src/net/http/cookiejar/jar.go +++ b/src/net/http/cookiejar/jar.go @@ -356,6 +356,13 @@ func jarKey(host string, psl PublicSuffixList) string { // isIP reports whether host is an IP address. func isIP(host string) bool { + if strings.ContainsAny(host, ":%") { + // Probable IPv6 address. + // Hostnames can't contain : or %, so this is definitely not a valid host. + // Treating it as an IP is the more conservative option, and avoids the risk + // of interpeting ::1%.www.example.com as a subtomain of www.example.com. + return true + } return net.ParseIP(host) != nil } diff --git a/src/net/http/cookiejar/jar_test.go b/src/net/http/cookiejar/jar_test.go index 47fb1ab..fd8d40e 100644 --- a/src/net/http/cookiejar/jar_test.go +++ b/src/net/http/cookiejar/jar_test.go @@ -251,6 +251,7 @@ var isIPTests = map[string]bool{ "127.0.0.1": true, "1.2.3.4": true, "2001:4860:0:2001::68": true, + "::1%zone": true, "example.com": false, "1.1.1.300": false, "www.foo.bar.net": false, @@ -613,6 +614,15 @@ var basicsTests = [...]jarTest{ {"http://www.host.test:1234/", "a=1"}, }, }, + { + "IPv6 zone is not treated as a host.", + "https://example.com/", + []string{"a=1"}, + "a=1", + []query{ + {"https://[::1%25.example.com]:80/", ""}, + }, + }, } func TestBasics(t *testing.T) { -- 2.25.1