squid: fix CVE-2023-46847 Denial of Service in HTTP Digest Authentication

Signed-off-by: Vivek Kumbhar <vkumbhar@mvista.com>
Signed-off-by: Armin Kuster <akuster808@gmail.com>

meta-networking/recipes-daemons/squid/files/CVE-2023-46847.patch

@@ -0,0 +1,47 @@
+From 052cf082b0faaef4eaaa4e94119d7a1437aac4a3 Mon Sep 17 00:00:00 2001
+From: squidadm <squidadm@users.noreply.github.com>
+Date: Wed, 18 Oct 2023 04:50:56 +1300
+Subject: [PATCH] Fix stack buffer overflow when parsing Digest Authorization
+ (#1517)
+
+The bug was discovered and detailed by Joshua Rogers at
+https://megamansec.github.io/Squid-Security-Audit/digest-overflow.html
+where it was filed as "Stack Buffer Overflow in Digest Authentication".
+
+---------
+
+Co-authored-by: Alex Bason <nonsleepr@gmail.com>
+Co-authored-by: Amos Jeffries <yadij@users.noreply.github.com>
+
+Upstream-Status: Backport [https://github.com/squid-cache/squid/commit/052cf082b0faaef4eaaa4e94119d7a1437aac4a3]
+CVE: CVE-2023-46847
+Signed-off-by: Vivek Kumbhar <vkumbhar@mvista.com>
+---
+ src/auth/digest/Config.cc | 10 +++++++---
+ 1 file changed, 7 insertions(+), 3 deletions(-)
+
+diff --git a/src/auth/digest/Config.cc b/src/auth/digest/Config.cc
+index 6a9736f..0a883fa 100644
+--- a/src/auth/digest/Config.cc
++++ b/src/auth/digest/Config.cc
+@@ -847,11 +847,15 @@ Auth::Digest::Config::decode(char const *proxy_auth, const char *aRequestRealm)
+             break;
+
+         case DIGEST_NC:
+-            if (value.size() != 8) {
++            if (value.size() == 8) {
++                // for historical reasons, the nc value MUST be exactly 8 bytes
++                static_assert(sizeof(digest_request->nc) == 8 + 1, "bad nc buffer size");
++                xstrncpy(digest_request->nc, value.rawBuf(), value.size() + 1);
++                debugs(29, 9, "Found noncecount '" << digest_request->nc << "'");
++            } else {
+                 debugs(29, 9, "Invalid nc '" << value << "' in '" << temp << "'");
++                digest_request->nc[0] = 0;
+             }
+-            xstrncpy(digest_request->nc, value.rawBuf(), value.size() + 1);
+-            debugs(29, 9, "Found noncecount '" << digest_request->nc << "'");
+             break;
+
+         case DIGEST_CNONCE:
+--
+2.40.1

meta-networking/recipes-daemons/squid/squid_4.15.bb

@@ -25,6 +25,7 @@ SRC_URI = "http://www.squid-cache.org/Versions/v${MAJ_VER}/${BPN}-${PV}.tar.bz2
            file://0001-tools.cc-fixed-unused-result-warning.patch \
            file://0001-splay.cc-fix-bind-is-not-a-member-of-std.patch \
            file://0001-Fix-build-on-Fedora-Rawhide-772.patch \
+           file://CVE-2023-46847.patch \
            "
 
 SRC_URI:remove:toolchain-clang = "file://0001-configure-Check-for-Wno-error-format-truncation-comp.patch"