From 5e728e929942d39ce5a4ab3d01c33f7b688c4e3f Mon Sep 17 00:00:00 2001 From: David Lamparter Date: Wed, 23 Jan 2013 05:50:24 +0100 Subject: bgpd: relax ORF capability length handling commit fe9bb64... "bgpd: CVE-2012-1820, DoS in bgp_capability_orf()" made the length test in bgp_capability_orf_entry() stricter and is now causing us to refuse (with CEASE) ORF capabilites carrying any excess data. This does not conform to the robustness principle as laid out by RFC1122 ("be liberal in what you accept"). Even worse, RFC5291 is quite unclear on how to use the ORF capability with multiple AFI/SAFIs. It can be interpreted as either "use one instance, stuff everything in" but also as "use multiple instances". So, if not for applying robustness, we end up clearing sessions from implementations going by the former interpretation. (or if anyone dares add a byte of padding...) Cc: Denis Ovsienko Signed-off-by: David Lamparter --- bgpd/bgp_open.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'bgpd') diff --git a/bgpd/bgp_open.c b/bgpd/bgp_open.c index af711cc8..7bf35016 100644 --- a/bgpd/bgp_open.c +++ b/bgpd/bgp_open.c @@ -230,7 +230,7 @@ bgp_capability_orf_entry (struct peer *peer, struct capability_header *hdr) } /* validate number field */ - if (sizeof (struct capability_orf_entry) + (entry.num * 2) != hdr->length) + if (sizeof (struct capability_orf_entry) + (entry.num * 2) > hdr->length) { zlog_info ("%s ORF Capability entry length error," " Cap length %u, num %u", -- cgit v1.2.1