gnu: Add libvnc.

* gnu/packages/vnc.scm (libvnc): New variable.
  gnu/packages/patches/libvnc-CVE-2018-20750.patch,
  gnu/packages/patches/libvnc-CVE-2019-15681.patch: New files.
* gnu/local.mk: Add them.

2 files changed, 67 insertions, 0 deletions

diff --git a/gnu/packages/patches/libvnc-CVE-2018-20750.patch b/gnu/packages/patches/libvnc-CVE-2018-20750.patch
new file mode 100644
index 0000000000..146243670a
--- /dev/null
+++ b/gnu/packages/patches/libvnc-CVE-2018-20750.patch
@@ -0,0 +1,44 @@
+From 09e8fc02f59f16e2583b34fe1a270c238bd9ffec Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Petr=20P=C3=ADsa=C5=99?= <ppisar@redhat.com>
+Date: Mon, 7 Jan 2019 10:40:01 +0100
+Subject: [PATCH] Limit lenght to INT_MAX bytes in
+ rfbProcessFileTransferReadBuffer()
+
+This ammends 15bb719c03cc70f14c36a843dcb16ed69b405707 fix for a heap
+out-of-bound write access in rfbProcessFileTransferReadBuffer() when
+reading a transfered file content in a server. The former fix did not
+work on platforms with a 32-bit int type (expected by rfbReadExact()).
+
+CVE-2018-15127
+<https://github.com/LibVNC/libvncserver/issues/243>
+<https://github.com/LibVNC/libvncserver/issues/273>
+---
+ libvncserver/rfbserver.c | 7 ++++++-
+ 1 file changed, 6 insertions(+), 1 deletion(-)
+
+diff --git a/libvncserver/rfbserver.c b/libvncserver/rfbserver.c
+index 7af84906..f2edbeea 100644
+--- a/libvncserver/rfbserver.c
++++ b/libvncserver/rfbserver.c
+@@ -88,6 +88,8 @@
+ #include <errno.h>
+ /* strftime() */
+ #include <time.h>
++/* INT_MAX */
++#include <limits.h>
+ 
+ #ifdef LIBVNCSERVER_WITH_WEBSOCKETS
+ #include "rfbssl.h"
+@@ -1472,8 +1474,11 @@ char *rfbProcessFileTransferReadBuffer(rfbClientPtr cl, uint32_t length)
+        0XFFFFFFFF, i.e. SIZE_MAX for 32-bit systems. On 64-bit systems, a length of 0XFFFFFFFF
+        will safely be allocated since this check will never trigger and malloc() can digest length+1
+        without problems as length is a uint32_t.
++       We also later pass length to rfbReadExact() that expects a signed int type and
++       that might wrap on platforms with a 32-bit int type if length is bigger
++       than 0X7FFFFFFF.
+     */
+-    if(length == SIZE_MAX) {
++    if(length == SIZE_MAX || length > INT_MAX) {
+ 	rfbErr("rfbProcessFileTransferReadBuffer: too big file transfer length requested: %u", (unsigned int)length);
+ 	rfbCloseClient(cl);
+ 	return NULL;
diff --git a/gnu/packages/patches/libvnc-CVE-2019-15681.patch b/gnu/packages/patches/libvnc-CVE-2019-15681.patch
new file mode 100644
index 0000000000..e328d87920
--- /dev/null
+++ b/gnu/packages/patches/libvnc-CVE-2019-15681.patch
@@ -0,0 +1,23 @@
+From d01e1bb4246323ba6fcee3b82ef1faa9b1dac82a Mon Sep 17 00:00:00 2001
+From: Christian Beier <dontmind@freeshell.org>
+Date: Mon, 19 Aug 2019 22:32:25 +0200
+Subject: [PATCH] rfbserver: don't leak stack memory to the remote
+
+Thanks go to Pavel Cheremushkin of Kaspersky for reporting.
+---
+ libvncserver/rfbserver.c | 2 ++
+ 1 file changed, 2 insertions(+)
+
+diff --git a/libvncserver/rfbserver.c b/libvncserver/rfbserver.c
+index 3bacc891..310e5487 100644
+--- a/libvncserver/rfbserver.c
++++ b/libvncserver/rfbserver.c
+@@ -3724,6 +3724,8 @@ rfbSendServerCutText(rfbScreenInfoPtr rfbScreen,char *str, int len)
+     rfbServerCutTextMsg sct;
+     rfbClientIteratorPtr iterator;
+ 
++    memset((char *)&sct, 0, sizeof(sct));
++
+     iterator = rfbGetClientIterator(rfbScreen);
+     while ((cl = rfbClientIteratorNext(iterator)) != NULL) {
+         sct.type = rfbServerCutText;