diff --git a/gnu-system.am b/gnu-system.am
index 3c8f402fa63fb4ad13c8b2ca6c3b0fa72ae24a8a..df177b62d550ea08ded1d19850539abbedb2aaeb 100644
--- a/gnu-system.am
+++ b/gnu-system.am
@@ -497,6 +497,7 @@ dist_patch_DATA = \
gnu/packages/patches/gobject-introspection-cc.patch \
gnu/packages/patches/gobject-introspection-girepository.patch \
gnu/packages/patches/grep-CVE-2015-1345.patch \
+ gnu/packages/patches/grub-CVE-2015-8370.patch \
gnu/packages/patches/grub-gets-undeclared.patch \
gnu/packages/patches/grub-freetype.patch \
gnu/packages/patches/guile-1.8-cpp-4.5.patch \
diff --git a/gnu/packages/grub.scm b/gnu/packages/grub.scm
index 79fc2f0aca370bc8a8b0b9c4ae70faf76e47283f..96d284c108c673c0cfa8a849edb3fa0b0533a706 100644
--- a/gnu/packages/grub.scm
+++ b/gnu/packages/grub.scm
@@ -1,6 +1,7 @@
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2013, 2014, 2015 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2015 Mark H Weaver <mhw@netris.org>
+;;; Copyright © 2015 Leo Famulari <leo@famulari.name>
;;;
;;; This file is part of GNU Guix.
;;;
@@ -83,7 +84,8 @@ (define-public grub
(base32
"0n64hpmsccvicagvr0c6v0kgp2yw0kgnd3jvsyd26cnwgs7c6kkq"))
(patches (list (search-patch "grub-gets-undeclared.patch")
- (search-patch "grub-freetype.patch")))))
+ (search-patch "grub-freetype.patch")
+ (search-patch "grub-CVE-2015-8370.patch")))))
(build-system gnu-build-system)
(arguments
'(#:configure-flags '("--disable-werror")
diff --git a/gnu/packages/patches/grub-CVE-2015-8370.patch b/gnu/packages/patches/grub-CVE-2015-8370.patch
new file mode 100644
index 0000000000000000000000000000000000000000..5701b54759fd2d1a674e5b3d66a5e9af33944279
--- /dev/null
+++ b/gnu/packages/patches/grub-CVE-2015-8370.patch
@@ -0,0 +1,45 @@
+From 88c9657960a6c5d3673a25c266781e876c181add Mon Sep 17 00:00:00 2001
+From: Hector Marco-Gisbert <hecmargi@upv.es>
+Date: Fri, 13 Nov 2015 16:21:09 +0100
+Subject: [PATCH] Fix security issue when reading username and password
+
+ This patch fixes two integer underflows at:
+ * grub-core/lib/crypto.c
+ * grub-core/normal/auth.c
+
+Signed-off-by: Hector Marco-Gisbert <hecmargi@upv.es>
+Signed-off-by: Ismael Ripoll-Ripoll <iripoll@disca.upv.es>
+---
+ grub-core/lib/crypto.c | 2 +-
+ grub-core/normal/auth.c | 2 +-
+ 2 files changed, 2 insertions(+), 2 deletions(-)
+
+diff --git a/grub-core/lib/crypto.c b/grub-core/lib/crypto.c
+index 010e550..524a3d8 100644
+--- a/grub-core/lib/crypto.c
++++ b/grub-core/lib/crypto.c
+@@ -468,7 +468,7 @@ grub_password_get (char buf[], unsigned buf_size)
+ break;
+ }
+
+- if (key == '\b')
++ if (key == '\b' && cur_len)
+ {
+ cur_len--;
+ continue;
+diff --git a/grub-core/normal/auth.c b/grub-core/normal/auth.c
+index c6bd96e..5782ec5 100644
+--- a/grub-core/normal/auth.c
++++ b/grub-core/normal/auth.c
+@@ -172,7 +172,7 @@ grub_username_get (char buf[], unsigned buf_size)
+ break;
+ }
+
+- if (key == '\b')
++ if (key == '\b' && cur_len)
+ {
+ cur_len--;
+ grub_printf ("\b");
+--
+1.9.1
+