go: fix CVE-2023-24539 html/template improper sanitization of CSS values

Angle brackets should not appear in CSS contexts, as they may affect
token boundaries (such as closing a <style> tag, resulting in
injection). Instead emit filterFailsafe, matching the behavior for other
dangerous characters.

Thanks to Juho Nurminen of Mattermost for reporting this issue.

For #59720
Fixes #59811
Fixes CVE-2023-24539

(From OE-Core rev: 0a09194f3d4ad98d0cf0d070ec0c99e7a6c8a158)

Signed-off-by: Vivek Kumbhar <vkumbhar@mvista.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>

2 files changed, 54 insertions, 0 deletions

diff --git a/meta/recipes-devtools/go/go-1.17.13.inc b/meta/recipes-devtools/go/go-1.17.13.inc
index e5e9d841c4..d430e0669d 100644
--- a/meta/recipes-devtools/go/go-1.17.13.inc
+++ b/meta/recipes-devtools/go/go-1.17.13.inc
@@ -31,6 +31,7 @@ SRC_URI += "\
     file://CVE-2023-24534.patch \
     file://CVE-2023-24538.patch \
     file://CVE-2023-24540.patch \
+    file://CVE-2023-24539.patch \
 "
 SRC_URI[main.sha256sum] = "a1a48b23afb206f95e7bbaa9b898d965f90826f6f1d1fc0c1d784ada0cd300fd"
 
diff --git a/meta/recipes-devtools/go/go-1.18/CVE-2023-24539.patch b/meta/recipes-devtools/go/go-1.18/CVE-2023-24539.patch
new file mode 100644
index 0000000000..fa19e18264
--- /dev/null
+++ b/meta/recipes-devtools/go/go-1.18/CVE-2023-24539.patch
@@ -0,0 +1,53 @@
+From e49282327b05192e46086bf25fd3ac691205fe80 Mon Sep 17 00:00:00 2001
+From: Roland Shoemaker <bracewell@google.com>
+Date: Thu, 13 Apr 2023 15:40:44 -0700
+Subject: [PATCH] [release-branch.go1.19] html/template: disallow angle
+ brackets in CSS values
+
+Change-Id: Iccc659c9a18415992b0c05c178792228e3a7bae4
+Reviewed-on: https://team-review.git.corp.google.com/c/golang/go-private/+/1826636
+Reviewed-by: Julie Qiu <julieqiu@google.com>
+Run-TryBot: Roland Shoemaker <bracewell@google.com>
+Reviewed-by: Damien Neil <dneil@google.com>
+Reviewed-on: https://team-review.git.corp.google.com/c/golang/go-private/+/1851496
+Run-TryBot: Damien Neil <dneil@google.com>
+Reviewed-by: Roland Shoemaker <bracewell@google.com>
+Reviewed-on: https://go-review.googlesource.com/c/go/+/491335
+Run-TryBot: Carlos Amedee <carlos@golang.org>
+Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
+TryBot-Result: Gopher Robot <gobot@golang.org>
+
+Upstream-Status: Backport [https://github.com/golang/go/commit/e49282327b05192e46086bf25fd3ac691205fe80]
+CVE: CVE-2023-24539
+Signed-off-by: Vivek Kumbhar <vkumbhar@mvista.com>
+---
+ src/html/template/css.go      | 2 +-
+ src/html/template/css_test.go | 2 ++
+ 2 files changed, 3 insertions(+), 1 deletion(-)
+
+diff --git a/src/html/template/css.go b/src/html/template/css.go
+index 890a0c6b227fe..f650d8b3e843a 100644
+--- a/src/html/template/css.go
++++ b/src/html/template/css.go
+@@ -238,7 +238,7 @@ func cssValueFilter(args ...any) string {
+        // inside a string that might embed JavaScript source.
+        for i, c := range b {
+                switch c {
+-               case 0, '"', '\'', '(', ')', '/', ';', '@', '[', '\\', ']', '`', '{', '}':
++               case 0, '"', '\'', '(', ')', '/', ';', '@', '[', '\\', ']', '`', '{', '}', '<', '>':
+                        return filterFailsafe
+                case '-':
+                        // Disallow <!-- or -->.
+diff --git a/src/html/template/css_test.go b/src/html/template/css_test.go
+index a735638b0314f..2b76256a766e9 100644
+--- a/src/html/template/css_test.go
++++ b/src/html/template/css_test.go
+@@ -231,6 +231,8 @@ func TestCSSValueFilter(t *testing.T) {
+                {`-exp\000052 ession(alert(1337))`, "ZgotmplZ"},
+                {`-expre\0000073sion`, "-expre\x073sion"},
+                {`@import url evil.css`, "ZgotmplZ"},
++               {"<", "ZgotmplZ"},
++               {">", "ZgotmplZ"},
+        }
+        for _, test := range tests {
+                got := cssValueFilter(test.css)