[Buildroot] [git commit] package/libvncserver: fix CVE-2018-20750
From: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Date: 2020-03-03 21:10:09
Subsystem:
the rest · Maintainer:
Linus Torvalds
commit: https://git.buildroot.net/buildroot/commit/?id=b10cee53265b0ddd195a26569caa8909d82e8c04 branch: https://git.buildroot.net/buildroot/commit/?id=refs/heads/master LibVNC through 0.9.12 contains a heap out-of-bounds write vulnerability in libvncserver/rfbserver.c. The fix for CVE-2018-15127 was incomplete. Signed-off-by: Fabrice Fontaine <redacted> Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com> --- ...bytes-in-rfbProcessFileTransferReadBuffer.patch | 47 ++++++++++++++++++++++ package/libvncserver/libvncserver.mk | 3 ++ 2 files changed, 50 insertions(+)
diff --git a/package/libvncserver/0003-Limit-lenght-to-INT_MAX-bytes-in-rfbProcessFileTransferReadBuffer.patch b/package/libvncserver/0003-Limit-lenght-to-INT_MAX-bytes-in-rfbProcessFileTransferReadBuffer.patch
new file mode 100644
index 0000000000..7461f11f80
--- /dev/null
+++ b/package/libvncserver/0003-Limit-lenght-to-INT_MAX-bytes-in-rfbProcessFileTransferReadBuffer.patch@@ -0,0 +1,47 @@ +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> +[Retrieved from: +https://github.com/LibVNC/libvncserver/commit/09e8fc02f59f16e2583b34fe1a270c238bd9ffec] +Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com> +--- + 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/package/libvncserver/libvncserver.mk b/package/libvncserver/libvncserver.mk
index b024c3161d..79db2dad83 100644
--- a/package/libvncserver/libvncserver.mk
+++ b/package/libvncserver/libvncserver.mk@@ -13,6 +13,9 @@ LIBVNCSERVER_INSTALL_STAGING = YES LIBVNCSERVER_DEPENDENCIES = host-pkgconf lzo LIBVNCSERVER_CONF_OPTS = -DWITH_LZO=ON +# 0003-Limit-lenght-to-INT_MAX-bytes-in-rfbProcessFileTransferReadBuffer.patch +LIBVNCSERVER_IGNORE_CVES += CVE-2018-20750 + # only used for examples LIBVNCSERVER_CONF_OPTS += \ -DWITH_FFMPEG=OFF \