From 41962435836dad34c9d0b3aa9eb3220f5340ea13 Mon Sep 17 00:00:00 2001 From: Russell Bryant Date: Mon, 5 Jun 2006 22:03:16 +0000 Subject: [PATCH] backport the chan_iax2 security fix from 1.2 and trunk ... ensure that the received number of bytes is included in all IAX2 incoming frame analysis checks (fixes a known vulnerability) git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.0@32428 65c4cc65-6c06-0410-ace0-fbb531ad65f3 --- channels/chan_iax2.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/channels/chan_iax2.c b/channels/chan_iax2.c index b1756efb36..d55734293b 100644 --- a/channels/chan_iax2.c +++ b/channels/chan_iax2.c @@ -5052,11 +5052,11 @@ static int socket_read(int *id, int fd, short events, void *cbdata) ast_log(LOG_WARNING, "midget packet received (%d of %d min)\n", res, (int)sizeof(struct ast_iax2_mini_hdr)); return 1; } - if ((vh->zeros == 0) && (ntohs(vh->callno) & 0x8000)) { + if ((res >= sizeof(*vh)) && ((vh->zeros == 0) && (ntohs(vh->callno) & 0x8000))) { /* This is a video frame, get call number */ fr.callno = find_callno(ntohs(vh->callno) & ~0x8000, dcallno, &sin, new, 1); minivid = 1; - } else if (meta->zeros == 0) { + } else if ((res >= sizeof(*meta)) && (meta->zeros == 0) && !(ntohs(meta->metacmd) & 0x8000)) { /* This is a meta header */ switch(meta->metacmd) { case IAX_META_TRUNK: @@ -5149,11 +5149,19 @@ static int socket_read(int *id, int fd, short events, void *cbdata) } return 1; } + /* if we got here and ->zeros contains zeros, this cannot be a valid + miniframe or full frame but it wasn't a valid video frame or meta + frame either, so we reject it + */ + if (vh->zeros == 0) { + ast_log(LOG_WARNING, "Rejecting packet from '%s.%d' that is flagged as a video or meta frame but is not properly formatted\n", ast_inet_ntoa(iabuf, sizeof(iabuf), sin.sin_addr), ntohs(sin.sin_port)); + return 1; + } #ifdef DEBUG_SUPPORT if (iaxdebug) iax_showframe(NULL, fh, 1, &sin, res - sizeof(struct ast_iax2_full_hdr)); #endif - if (ntohs(mh->callno) & IAX_FLAG_FULL) { + if ((res >= sizeof(*fh)) && ntohs(mh->callno) & IAX_FLAG_FULL) { /* Get the destination call number */ dcallno = ntohs(fh->dcallno) & ~IAX_FLAG_RETRANS; /* Retrieve the type and subclass */