From c14b8b511ac55f6933aebefbd6cc27c1ec74ad58 Mon Sep 17 00:00:00 2001 From: Simon Kelley Date: Mon, 25 Sep 2017 18:47:15 +0100 Subject: [PATCH 2/9] Security fix, CVE-2017-14492, DHCPv6 RA heap overflow. Fix heap overflow in IPv6 router advertisement code. This is a potentially serious security hole, as a crafted RA request can overflow a buffer and crash or control dnsmasq. Attacker must be on the local network. --- src/radv.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/src/radv.c b/src/radv.c index 749b666..d09fe0e 100644 --- a/src/radv.c +++ b/src/radv.c @@ -198,6 +198,9 @@ void icmp6_packet(time_t now) /* look for link-layer address option for logging */ if (sz >= 16 && packet[8] == ICMP6_OPT_SOURCE_MAC && (packet[9] * 8) + 8 <= sz) { + if ((packet[9] * 8 - 2) * 3 - 1 >= MAXDNAME) { + return; + } print_mac(daemon->namebuff, &packet[10], (packet[9] * 8) - 2); mac = daemon->namebuff; } -- 2.9.5