Fix CVE-2020-29074 (insecure permissions on a shared memory)

https://fedoraproject.org/wiki/Changes/Remove_make_from_BuildRoot

x11vnc-0.9.16-scan-limit-access-to-shared-memory-segments-to-curre.patch

@@ -0,0 +1,29 @@
+From 69eeb9f7baa14ca03b16c9de821f9876def7a36a Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Gu=C3=A9nal=20DAVALAN?= <guenal.davalan@uca.fr>
+Date: Wed, 18 Nov 2020 08:40:45 +0100
+Subject: [PATCH] scan: limit access to shared memory segments to current user
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Signed-off-by: Petr Písař <ppisar@redhat.com>
+---
+ src/scan.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/src/scan.c b/src/scan.c
+index 43e00d2..12994d5 100644
+--- a/src/scan.c
++++ b/src/scan.c
+@@ -320,7 +320,7 @@ static int shm_create(XShmSegmentInfo *shm, XImage **ximg_ptr, int w, int h,
+ 
+ #if HAVE_XSHM
+ 	shm->shmid = shmget(IPC_PRIVATE,
+-	    xim->bytes_per_line * xim->height, IPC_CREAT | 0777);
++	    xim->bytes_per_line * xim->height, IPC_CREAT | 0600);
+ 
+ 	if (shm->shmid == -1) {
+ 		rfbErr("shmget(%s) failed.\n", name);
+-- 
+2.26.2
+

x11vnc.spec

@@ -1,6 +1,6 @@
 Name:           x11vnc
 Version:        0.9.16
-Release:        2%{?dist}
+Release:        3%{?dist}
 Summary:        VNC server for the current X11 session
 Summary(ru):    VNC-сервер для текущей сессии X11
 # COPYING:                  GPLv2 text
@@ -57,6 +57,9 @@ Patch2:         x11vnc-0.9.16-Fix-build-with-fno-common.patch
 # Fix a NULL pointer dereference in a cursor handler, upstream bug #123, in
 # upstream after 0.9.16
 Patch3:         x11vnc-0.9.16-src-cursor-fix-xfc-NULL-pointer-dereference.patch
+# Fix CVE-2020-29074 (insecure permissions on a shared memory), bug #1933603,
+# in upstream after 0.9.16
+Patch4:         x11vnc-0.9.16-scan-limit-access-to-shared-memory-segments-to-curre.patch
 BuildRequires:  autoconf
 BuildRequires:  automake
 # for autogen.sh script
@@ -70,6 +73,7 @@ BuildRequires:  libXfixes-devel
 BuildRequires:  libXinerama-devel
 BuildRequires:  libXrandr-devel
 BuildRequires:  libXtst-devel
+BuildRequires:  make
 BuildRequires:  openssl-devel
 BuildRequires:  pkgconf-pkg-config
 BuildRequires:  pkgconfig(avahi-client) >= 0.6.4
@@ -113,6 +117,7 @@ a versatile and productive while still easy to use program.
 %patch1 -p1
 %patch2 -p1
 %patch3 -p1
+%patch4 -p1
 
 %build
 autoreconf -fi
@@ -153,6 +158,9 @@ desktop-file-validate %{buildroot}/%{_datadir}/applications/x11vnc.desktop
 %{_mandir}/man1/x11vnc.1*
 
 %changelog
+* Mon Mar 01 2021 Petr Pisar <ppisar@redhat.com> - 0.9.16-3
+- Fix CVE-2020-29074 (insecure permissions on a shared memory) (bug #1933603)
+
 * Mon Apr 06 2020 Petr Pisar <ppisar@redhat.com> - 0.9.16-2
 - Modernize a spec file
 - License corrected from GPLv2 to GPLv2+