Malicious RDP server security fixes

This commit includes fixes for a set of 21 vulnerabilities in
rdesktop when a malicious RDP server is used.

All vulnerabilities was identified and reported by Eyal Itkin.

 * Add rdp_protocol_error function that is used in several fixes
 * Refactor of process_bitmap_updates
 * Fix possible integer overflow in s_check_rem() on 32bit arch
 * Fix memory corruption in process_bitmap_data - CVE-2018-8794
 * Fix remote code execution in process_bitmap_data - CVE-2018-8795
 * Fix remote code execution in process_plane - CVE-2018-8797
 * Fix Denial of Service in mcs_recv_connect_response - CVE-2018-20175
 * Fix Denial of Service in mcs_parse_domain_params - CVE-2018-20175
 * Fix Denial of Service in sec_parse_crypt_info - CVE-2018-20176
 * Fix Denial of Service in sec_recv - CVE-2018-20176
 * Fix minor information leak in rdpdr_process - CVE-2018-8791
 * Fix Denial of Service in cssp_read_tsrequest - CVE-2018-8792
 * Fix remote code execution in cssp_read_tsrequest - CVE-2018-8793
 * Fix Denial of Service in process_bitmap_data - CVE-2018-8796
 * Fix minor information leak in rdpsnd_process_ping - CVE-2018-8798
 * Fix Denial of Service in process_secondary_order - CVE-2018-8799
 * Fix remote code execution in in ui_clip_handle_data - CVE-2018-8800
 * Fix major information leak in ui_clip_handle_data - CVE-2018-20174
 * Fix memory corruption in rdp_in_unistr - CVE-2018-20177
 * Fix Denial of Service in process_demand_active - CVE-2018-20178
 * Fix remote code execution in lspci_process - CVE-2018-20179
 * Fix remote code execution in rdpsnddbg_process - CVE-2018-20180
 * Fix remote code execution in seamless_process - CVE-2018-20181
 * Fix remote code execution in seamless_process_line - CVE-2018-20182

asn.c

@@ -22,7 +22,7 @@
 
 /* Parse an ASN.1 BER header */
 RD_BOOL
-ber_parse_header(STREAM s, int tagval, int *length)
+ber_parse_header(STREAM s, int tagval, uint32 *length)
 {
 	int tag, len;
 

bitmap.c

@@ -794,15 +794,15 @@ process_plane(uint8 * in, int width, int height, uint8 * out, int size)
 					replen = revcode;
 					collen = 0;
 				}
-				while (collen > 0)
+				while (indexw < width && collen > 0)
 				{
 					color = CVAL(in);
 					*out = color;
 					out += 4;
 					indexw++;
 					collen--;
 				}
-				while (replen > 0)
+				while (indexw < width && replen > 0)
 				{
 					*out = color;
 					out += 4;
@@ -824,7 +824,7 @@ process_plane(uint8 * in, int width, int height, uint8 * out, int size)
 					replen = revcode;
 					collen = 0;
 				}
-				while (collen > 0)
+				while (indexw < width && collen > 0)
 				{
 					x = CVAL(in);
 					if (x & 1)
@@ -844,7 +844,7 @@ process_plane(uint8 * in, int width, int height, uint8 * out, int size)
 					indexw++;
 					collen--;
 				}
-				while (replen > 0)
+				while (indexw < width && replen > 0)
 				{
 					x = last_line[indexw * 4] + color;
 					*out = x;

cliprdr.c

@@ -118,6 +118,7 @@ cliprdr_process(STREAM s)
 	uint16 type, status;
 	uint32 length, format;
 	uint8 *data;
+	struct stream packet = *s;
 
 	in_uint16_le(s, type);
 	in_uint16_le(s, status);
@@ -127,6 +128,11 @@ cliprdr_process(STREAM s)
 	logger(Clipboard, Debug, "cliprdr_process(), type=%d, status=%d, length=%d", type, status,
 	       length);
 
+	if (!s_check_rem(s, length))
+	{
+		rdp_protocol_error("cliprdr_process(), consume of packet from stream would overrun", &packet);
+	}
+
 	if (status == CLIPRDR_ERROR)
 	{
 		switch (type)

constants.h

@@ -751,6 +751,9 @@ enum RDP_DESKTOP_ORIENTATION
 #define ENC_SALTED_CHECKSUM		0x0010
 #define NO_BITMAP_COMPRESSION_HDR	0x0400
 
+/* [MS-RDPBCGR], TS_BITMAP_DATA, flags */
+#define BITMAP_COMPRESSION              0x0001
+
 /* orderFlags, [MS-RDPBCGR] 2.2.7.1.3 */
 #define NEGOTIATEORDERSUPPORT	0x0002
 #define ZEROBOUNDSDELTASSUPPORT 0x0008

cssp.c

@@ -595,6 +595,7 @@ cssp_read_tsrequest(STREAM token, STREAM pubkey)
 	STREAM s;
 	int length;
 	int tagval;
+	struct stream packet;
 
 	s = tcp_recv(NULL, 4);
 
@@ -622,6 +623,7 @@ cssp_read_tsrequest(STREAM token, STREAM pubkey)
 
 	// receive the remainings of message
 	s = tcp_recv(s, length);
+	packet = *s;
 
 	// parse the response and into nego token
 	if (!ber_in_header(s, &tagval, &length) ||
@@ -632,6 +634,12 @@ cssp_read_tsrequest(STREAM token, STREAM pubkey)
 	if (!ber_in_header(s, &tagval, &length) ||
 	    tagval != (BER_TAG_CTXT_SPECIFIC | BER_TAG_CONSTRUCTED | 0))
 		return False;
+
+	if (!s_check_rem(s, length))
+	{
+		 rdp_protocol_error("cssp_read_tsrequest(), consume of version from stream would overrun",
+				    &packet);
+	}
 	in_uint8s(s, length);
 
 	// negoToken [1]
@@ -653,7 +661,14 @@ cssp_read_tsrequest(STREAM token, STREAM pubkey)
 		if (!ber_in_header(s, &tagval, &length) || tagval != BER_TAG_OCTET_STRING)
 			return False;
 
-		token->end = token->p = token->data;
+		if (!s_check_rem(s, length))
+		{
+			rdp_protocol_error("cssp_read_tsrequest(), consume of token from stream would overrun",
+					   &packet);
+		}
+
+		s_realloc(token, length);
+		s_reset(token);
 		out_uint8p(token, s->p, length);
 		s_mark_end(token);
 	}

lspci.c

@@ -1,7 +1,8 @@
 /*  -*- c-basic-offset: 8 -*-
    rdesktop: A Remote Desktop Protocol client.
    Support for the Matrox "lspci" channel
-   Copyright (C) 2005 Matrox Graphics Inc. 
+   Copyright (C) 2005 Matrox Graphics Inc.
+   Copyright 2018 Henrik Andersson <hean01@cendio.se> for Cendio AB
 
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -134,6 +135,12 @@ lspci_process(STREAM s)
 	unsigned int pkglen;
 	static char *rest = NULL;
 	char *buf;
+	struct stream packet = *s;
+
+	if (!s_check(s))
+	{
+		rdp_protocol_error("lspci_process(), stream is in unstable state", &packet);
+	}
 
 	pkglen = s->end - s->p;
 	/* str_handle_lines requires null terminated strings */

mcs.c

@@ -45,9 +45,16 @@ mcs_out_domain_params(STREAM s, int max_channels, int max_users, int max_tokens,
 static RD_BOOL
 mcs_parse_domain_params(STREAM s)
 {
-	int length;
+	uint32 length;
+	struct stream packet = *s;
 
 	ber_parse_header(s, MCS_TAG_DOMAIN_PARAMS, &length);
+
+	if (!s_check_rem(s, length))
+	{
+		rdp_protocol_error("mcs_parse_domain_params(), consume domain params from stream would overrun", &packet);
+	}
+
 	in_uint8s(s, length);
 
 	return s_check(s);
@@ -89,8 +96,9 @@ mcs_recv_connect_response(STREAM mcs_data)
 {
 	UNUSED(mcs_data);
 	uint8 result;
-	int length;
+	uint32 length;
 	STREAM s;
+	struct stream packet;
 	RD_BOOL is_fastpath;
 	uint8 fastpath_hdr;
 
@@ -99,6 +107,8 @@ mcs_recv_connect_response(STREAM mcs_data)
 
 	if (s == NULL)
 		return False;
+
+	packet = *s;
 
 	ber_parse_header(s, MCS_CONNECT_RESPONSE, &length);
 
@@ -112,6 +122,12 @@ mcs_recv_connect_response(STREAM mcs_data)
 
 	ber_parse_header(s, BER_TAG_INTEGER, &length);
 	in_uint8s(s, length);	/* connect id */
+
+	if (!s_check_rem(s, length))
+	{
+		rdp_protocol_error("mcs_recv_connect_response(), consume connect id from stream would overrun", &packet);
+	}
+
 	mcs_parse_domain_params(s);
 
 	ber_parse_header(s, BER_TAG_OCTET_STRING, &length);

orders.c

@@ -1259,11 +1259,17 @@ process_secondary_order(STREAM s)
 	uint16 flags;
 	uint8 type;
 	uint8 *next_order;
+	struct stream packet = *s;
 
 	in_uint16_le(s, length);
 	in_uint16_le(s, flags);	/* used by bmpcache2 */
 	in_uint8(s, type);
 
+	if (!s_check_rem(s, length + 7))
+	{
+		rdp_protocol_error("process_secondary_order(), next order pointer would overrun stream", &packet);
+	}
+
 	next_order = s->p + (sint16) length + 7;
 
 	switch (type)

proto.h

@@ -164,6 +164,7 @@ RD_BOOL rdp_connect(char *server, uint32 flags, char *domain, char *password, ch
 		    char *directory, RD_BOOL reconnect);
 void rdp_reset_state(void);
 void rdp_disconnect(void);
+void rdp_protocol_error(const char *message, STREAM s);
 /* rdpdr.c */
 int get_device_index(RD_NTHANDLE handle);
 void convert_to_unix_filename(char *filename);
@@ -224,7 +225,7 @@ void tcp_run_ui(RD_BOOL run);
 /* asn.c */
 RD_BOOL ber_in_header(STREAM s, int *tagval, int *length);
 void ber_out_header(STREAM s, int tagval, int length);
-RD_BOOL ber_parse_header(STREAM s, int tagval, int *length);
+RD_BOOL ber_parse_header(STREAM s, int tagval, uint32 *length);
 void ber_out_integer(STREAM s, int value);
 void ber_out_sequence(STREAM s, STREAM contents);