Security fix, CVE-2017-14493, DHCPv6 - Stack buffer overflow.

Fix stack overflow in DHCPv6 code. An attacker who can send
a DHCPv6 request to dnsmasq can overflow the stack frame and
crash or control dnsmasq.

Signed-off-by: Petr Menšík <pemensik@redhat.com>
This commit is contained in:
Petr Menšík 2017-09-26 17:53:25 +02:00
parent 2daf3ff20f
commit e84d4fc50e
2 changed files with 35 additions and 2 deletions

View File

@ -0,0 +1,30 @@
From 3d4ff1ba8419546490b464418223132529514033 Mon Sep 17 00:00:00 2001
From: Simon Kelley <simon@thekelleys.org.uk>
Date: Mon, 25 Sep 2017 18:52:50 +0100
Subject: [PATCH 4/9] Security fix, CVE-2017-14493, DHCPv6 - Stack buffer
overflow.
Fix stack overflow in DHCPv6 code. An attacker who can send
a DHCPv6 request to dnsmasq can overflow the stack frame and
crash or control dnsmasq.
---
src/rfc3315.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/src/rfc3315.c b/src/rfc3315.c
index 1687931..920907c 100644
--- a/src/rfc3315.c
+++ b/src/rfc3315.c
@@ -206,6 +206,9 @@ static int dhcp6_maybe_relay(struct state *state, void *inbuff, size_t sz,
/* RFC-6939 */
if ((opt = opt6_find(opts, end, OPTION6_CLIENT_MAC, 3)))
{
+ if (opt6_len(opt) - 2 > DHCP_CHADDR_MAX) {
+ return 0;
+ }
state->mac_type = opt6_uint(opt, 0, 2);
state->mac_len = opt6_len(opt) - 2;
memcpy(&state->mac[0], opt6_ptr(opt, 2), state->mac_len);
--
2.9.5

View File

@ -25,6 +25,7 @@ Source1: %{name}.service
Patch1: dnsmasq-2.77-CVE-2017-13704.patch
Patch2: dnsmasq-2.77-CVE-2017-14491.patch
Patch3: dnsmasq-2.77-CVE-2017-14492.patch
Patch4: dnsmasq-2.77-CVE-2017-14493.patch
BuildRoot: %{_tmppath}/%{name}-%{version}-%{release}-root-%(%{__id_u} -n)
@ -62,6 +63,7 @@ query/remove a DHCP server's leases.
%patch1 -p1 -b .CVE-2017-13704
%patch2 -p1 -b .CVE-2017-14491
%patch3 -p1 -b .CVE-2017-14492
%patch4 -p1 -b .CVE-2017-14493
# use /var/lib/dnsmasq instead of /var/lib/misc
for file in dnsmasq.conf.example man/dnsmasq.8 man/es/dnsmasq.8 src/config.h; do
@ -149,8 +151,9 @@ rm -rf $RPM_BUILD_ROOT
%changelog
* Mon Oct 02 2017 Petr Menšík <pemensik@redhat.com> - 2.77-8
- Security fix, CVE-2017-14491 DNS heap buffer overflow
- Security fix, CVE-2017-14492 DHCPv6 RA heap overflow
- Security fix, CVE-2017-14491, DNS heap buffer overflow
- Security fix, CVE-2017-14492, DHCPv6 RA heap overflow
- Security fix, CVE-2017-14493, DHCPv6 - Stack buffer overflow
* Thu Sep 14 2017 Petr Menšík <pemensik@redhat.com> - 2.77-7
- Fix CVE-2017-13704