From 870394c0513d773c6c8cab9573bd27640281359e Mon Sep 17 00:00:00 2001
From: Kevin Harwell <kharwell@digium.com>
Date: Thu, 12 Jun 2014 14:39:29 +0000
Subject: [PATCH] res_pjsip_pubsub: unauthenticated remote crash in PJSIP
pub/sub framework
A remotely exploitable crash vulnerability exists in the PJSIP channel driver's
pub/sub framework. If an attempt is made to unsubscribe when not currently
subscribed and the endpoint's "sub_min_expiry" is set to zero, Asterisk tries
to create an expiration timer with zero seconds, which is not allowed, so an
assertion raised.
The fix was to reject a subscription that is attempting to unsubscribe when not
being already subscribed. Asterisk now checks for this situation appropriately
and responds with a 400 instead of crashing.
AST-2014-005
ASTERISK-23489 #close
........
Merged revisions 415812 from http://svn.asterisk.org/svn/asterisk/branches/12
git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@415813 65c4cc65-6c06-0410-ace0-fbb531ad65f3
---
res/res_pjsip_pubsub.c | 18 +++++++++++++-----
1 file changed, 13 insertions(+), 5 deletions(-)
diff --git a/res/res_pjsip_pubsub.c b/res/res_pjsip_pubsub.c
index 88e284fafb..381f37617d 100644
--- a/res/res_pjsip_pubsub.c
+++ b/res/res_pjsip_pubsub.c
@@ -1129,12 +1129,20 @@ static pj_bool_t pubsub_on_rx_subscribe_request(pjsip_rx_data *rdata)
expires_header = pjsip_msg_find_hdr(rdata->msg_info.msg, PJSIP_H_EXPIRES, rdata->msg_info.msg->hdr.next);
- if (expires_header && expires_header->ivalue < endpoint->subscription.minexpiry) {
- ast_log(LOG_WARNING, "Subscription expiration %d is too brief for endpoint %s. Minimum is %u\n",
+ if (expires_header) {
+ if (expires_header->ivalue == 0) {
+ ast_log(LOG_WARNING, "Susbscription request from endpoint %s rejected. Expiration of 0 is invalid\n",
+ ast_sorcery_object_get_id(endpoint));
+ pjsip_endpt_respond_stateless(ast_sip_get_pjsip_endpoint(), rdata, 400, NULL, NULL, NULL);
+ return PJ_TRUE;
+ }
+ if (expires_header->ivalue < endpoint->subscription.minexpiry) {
+ ast_log(LOG_WARNING, "Subscription expiration %d is too brief for endpoint %s. Minimum is %d\n",
expires_header->ivalue, ast_sorcery_object_get_id(endpoint), endpoint->subscription.minexpiry);
- pjsip_endpt_respond_stateless(ast_sip_get_pjsip_endpoint(), rdata, 423, NULL, NULL, NULL);
- return PJ_TRUE;
- }
+ pjsip_endpt_respond_stateless(ast_sip_get_pjsip_endpoint(), rdata, 423, NULL, NULL, NULL);
+ return PJ_TRUE;
+ }
+ }
handler = subscription_get_handler_from_rdata(rdata);
if (!handler) {
--
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