Date: Sun, 14 Jan 2018 22:35:00 +0000 (UTC) From: Ben Woods <woodsb02@FreeBSD.org> To: ports-committers@freebsd.org, svn-ports-all@freebsd.org, svn-ports-head@freebsd.org Subject: svn commit: r459011 - in head/net-p2p: transmission-cli/files transmission-daemon Message-ID: <201801142235.w0EMZ0uV088748@repo.freebsd.org>
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Author: woodsb02 Date: Sun Jan 14 22:35:00 2018 New Revision: 459011 URL: https://svnweb.freebsd.org/changeset/ports/459011 Log: net-p2p/transmission-daemon: Mitigate DNS rebinding attack Incorporate upstream pull request 468, proposed by Tavis Ormandy from Google Project Zero, which mitigates this attack by requiring a host whitelist for requests that cannot be proven to be secure, but it can be disabled if a user does not want security. PR: 225150 Submitted by: Tavis Ormandy Approved by: crees (maintainer) Obtained from: https://github.com/transmission/transmission/pull/468#issuecomment-357098126 MFH: 2018Q1 Security: https://www.vuxml.org/freebsd/3e5b8bd3-0c32-452f-a60e-beab7b762351.html Added: head/net-p2p/transmission-cli/files/patch-fix_dns_rebinding_vuln (contents, props changed) Modified: head/net-p2p/transmission-daemon/Makefile Added: head/net-p2p/transmission-cli/files/patch-fix_dns_rebinding_vuln ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ head/net-p2p/transmission-cli/files/patch-fix_dns_rebinding_vuln Sun Jan 14 22:35:00 2018 (r459011) @@ -0,0 +1,302 @@ +Fix a weakness that allows remote code execution via the Transmission +RPC server using DNS rebinding: + +https://bugs.chromium.org/p/project-zero/issues/detail?id=1447 + +Patch adapted from Tavis Ormandy's patch on the Transmission master +branch to the Transmission 2.92 release by Leo Famulari +<leo@famulari.name>: + +https://github.com/transmission/transmission/pull/468/commits + +From fe2d3c6e75088f3d9b6040ce06da3d530358bc2f Mon Sep 17 00:00:00 2001 +From: Tavis Ormandy <taviso@google.com> +Date: Thu, 11 Jan 2018 10:00:41 -0800 +Subject: [PATCH] mitigate dns rebinding attacks against daemon + +--- + libtransmission/quark.c | 2 + + libtransmission/quark.h | 2 + + libtransmission/rpc-server.c | 116 +++++++++++++++++++++++++++++++++++++---- + libtransmission/rpc-server.h | 4 ++ + libtransmission/session.c | 2 + + libtransmission/transmission.h | 1 + + libtransmission/web.c | 3 ++ + 7 files changed, 121 insertions(+), 9 deletions(-) + +diff --git a/libtransmission/quark.c b/libtransmission/quark.c +index 30cc2bca4..b4fd7aabd 100644 +--- libtransmission/quark.c.orig ++++ libtransmission/quark.c +@@ -289,6 +289,8 @@ static const struct tr_key_struct my_static[] = + { "rpc-authentication-required", 27 }, + { "rpc-bind-address", 16 }, + { "rpc-enabled", 11 }, ++ { "rpc-host-whitelist", 18 }, ++ { "rpc-host-whitelist-enabled", 26 }, + { "rpc-password", 12 }, + { "rpc-port", 8 }, + { "rpc-url", 7 }, +diff --git a/libtransmission/quark.h b/libtransmission/quark.h +index 7f5212733..17464be8f 100644 +--- libtransmission/quark.h.orig ++++ libtransmission/quark.h +@@ -291,6 +291,8 @@ enum + TR_KEY_rpc_authentication_required, + TR_KEY_rpc_bind_address, + TR_KEY_rpc_enabled, ++ TR_KEY_rpc_host_whitelist, ++ TR_KEY_rpc_host_whitelist_enabled, + TR_KEY_rpc_password, + TR_KEY_rpc_port, + TR_KEY_rpc_url, +diff --git a/libtransmission/rpc-server.c b/libtransmission/rpc-server.c +index a3485f3fa..292cd5fce 100644 +--- libtransmission/rpc-server.c.orig ++++ libtransmission/rpc-server.c +@@ -52,6 +52,7 @@ struct tr_rpc_server + bool isEnabled; + bool isPasswordEnabled; + bool isWhitelistEnabled; ++ bool isHostWhitelistEnabled; + tr_port port; + char * url; + struct in_addr bindAddress; +@@ -63,6 +64,7 @@ struct tr_rpc_server + char * password; + char * whitelistStr; + tr_list * whitelist; ++ tr_list * hostWhitelist; + + char * sessionId; + time_t sessionIdExpiresAt; +@@ -588,6 +590,49 @@ isAddressAllowed (const tr_rpc_server * server, const char * address) + return false; + } + ++static bool isHostnameAllowed(tr_rpc_server const* server, struct evhttp_request* req) ++{ ++ /* If password auth is enabled, any hostname is permitted. */ ++ if (server->isPasswordEnabled) ++ { ++ return true; ++ } ++ ++ char const* const host = evhttp_find_header(req->input_headers, "Host"); ++ ++ // If whitelist is disabled, no restrictions. ++ if (!server->isHostWhitelistEnabled) ++ return true; ++ ++ /* No host header, invalid request. */ ++ if (host == NULL) ++ { ++ return false; ++ } ++ ++ /* Host header might include the port. */ ++ char* const hostname = tr_strndup(host, strcspn(host, ":")); ++ ++ /* localhost or ipaddress is always acceptable. */ ++ if (strcmp(hostname, "localhost") == 0 || strcmp(hostname, "localhost.") == 0 || tr_addressIsIP(hostname)) ++ { ++ tr_free(hostname); ++ return true; ++ } ++ ++ /* Otherwise, hostname must be whitelisted. */ ++ for (tr_list* l = server->hostWhitelist; l != NULL; l = l->next) { ++ if (tr_wildmat(hostname, l->data)) ++ { ++ tr_free(hostname); ++ return true; ++ } ++ } ++ ++ tr_free(hostname); ++ return false; ++} ++ + static bool + test_session_id (struct tr_rpc_server * server, struct evhttp_request * req) + { +@@ -663,6 +708,23 @@ handle_request (struct evhttp_request * req, void * arg) + handle_upload (req, server); + } + #ifdef REQUIRE_SESSION_ID ++ else if (!isHostnameAllowed(server, req)) ++ { ++ char* tmp = tr_strdup_printf( ++ "<p>Transmission received your request, but the hostname was unrecognized.</p>" ++ "<p>To fix this, choose one of the following options:" ++ "<ul>" ++ "<li>Enable password authentication, then any hostname is allowed.</li>" ++ "<li>Add the hostname you want to use to the whitelist in settings.</li>" ++ "</ul></p>" ++ "<p>If you're editing settings.json, see the 'rpc-host-whitelist' and 'rpc-host-whitelist-enabled' entries.</p>" ++ "<p>This requirement has been added to help prevent " ++ "<a href=\"https://en.wikipedia.org/wiki/DNS_rebinding\">DNS Rebinding</a> " ++ "attacks.</p>"); ++ send_simple_response(req, 421, tmp); ++ tr_free(tmp); ++ } ++ + else if (!test_session_id (server, req)) + { + const char * sessionId = get_current_session_id (server); +@@ -674,7 +736,7 @@ handle_request (struct evhttp_request * req, void * arg) + "<li> When you get this 409 error message, resend your request with the updated header" + "</ol></p>" + "<p>This requirement has been added to help prevent " +- "<a href=\"http://en.wikipedia.org/wiki/Cross-site_request_forgery\">CSRF</a>; " ++ "<a href=\"https://en.wikipedia.org/wiki/Cross-site_request_forgery\">CSRF</a>; " + "attacks.</p>" + "<p><code>%s: %s</code></p>", + TR_RPC_SESSION_ID_HEADER, sessionId); +@@ -875,19 +937,14 @@ tr_rpcGetUrl (const tr_rpc_server * server) + return server->url ? server->url : ""; + } + +-void +-tr_rpcSetWhitelist (tr_rpc_server * server, const char * whitelistStr) ++static void ++tr_rpcSetList (char const* whitelistStr, tr_list** list) + { + void * tmp; + const char * walk; + +- /* keep the string */ +- tmp = server->whitelistStr; +- server->whitelistStr = tr_strdup (whitelistStr); +- tr_free (tmp); +- + /* clear out the old whitelist entries */ +- while ((tmp = tr_list_pop_front (&server->whitelist))) ++ while ((tmp = tr_list_pop_front (list)) != NULL) + tr_free (tmp); + + /* build the new whitelist entries */ +@@ -896,7 +953,7 @@ tr_rpcSetWhitelist (tr_rpc_server * server, const char * whitelistStr) + const char * delimiters = " ,;"; + const size_t len = strcspn (walk, delimiters); + char * token = tr_strndup (walk, len); +- tr_list_append (&server->whitelist, token); ++ tr_list_append (list, token); + if (strcspn (token, "+-") < len) + tr_logAddNamedInfo (MY_NAME, "Adding address to whitelist: %s (And it has a '+' or '-'! Are you using an old ACL by mistake?)", token); + else +@@ -909,6 +966,21 @@ tr_rpcSetWhitelist (tr_rpc_server * server, const char * whitelistStr) + } + } + ++void tr_rpcSetHostWhitelist(tr_rpc_server* server, char const* whitelistStr) ++{ ++ tr_rpcSetList(whitelistStr, &server->hostWhitelist); ++} ++ ++void tr_rpcSetWhitelist(tr_rpc_server* server, char const* whitelistStr) ++{ ++ /* keep the string */ ++ char* const tmp = server->whitelistStr; ++ server->whitelistStr = tr_strdup(whitelistStr); ++ tr_free(tmp); ++ ++ tr_rpcSetList(whitelistStr, &server->whitelist); ++} ++ + const char* + tr_rpcGetWhitelist (const tr_rpc_server * server) + { +@@ -930,6 +1002,11 @@ tr_rpcGetWhitelistEnabled (const tr_rpc_server * server) + return server->isWhitelistEnabled; + } + ++void tr_rpcSetHostWhitelistEnabled(tr_rpc_server* server, bool isEnabled) ++{ ++ server->isHostWhitelistEnabled = isEnabled; ++} ++ + /**** + ***** PASSWORD + ****/ +@@ -1063,6 +1140,28 @@ tr_rpcInit (tr_session * session, tr_variant * settings) + else + tr_rpcSetWhitelistEnabled (s, boolVal); + ++ key = TR_KEY_rpc_host_whitelist_enabled; ++ ++ if (!tr_variantDictFindBool(settings, key, &boolVal)) ++ { ++ missing_settings_key(key); ++ } ++ else ++ { ++ tr_rpcSetHostWhitelistEnabled(s, boolVal); ++ } ++ ++ key = TR_KEY_rpc_host_whitelist; ++ ++ if (!tr_variantDictFindStr(settings, key, &str, NULL) && str != NULL) ++ { ++ missing_settings_key(key); ++ } ++ else ++ { ++ tr_rpcSetHostWhitelist(s, str); ++ } ++ + key = TR_KEY_rpc_authentication_required; + if (!tr_variantDictFindBool (settings, key, &boolVal)) + missing_settings_key (key); +diff --git a/libtransmission/rpc-server.h b/libtransmission/rpc-server.h +index e0302c5ea..8c9e6b24e 100644 +--- libtransmission/rpc-server.h.orig ++++ libtransmission/rpc-server.h +@@ -49,6 +49,10 @@ void tr_rpcSetWhitelist (tr_rpc_server * server, + + const char* tr_rpcGetWhitelist (const tr_rpc_server * server); + ++void tr_rpcSetHostWhitelistEnabled(tr_rpc_server* server, bool isEnabled); ++ ++void tr_rpcSetHostWhitelist(tr_rpc_server* server, char const* whitelist); ++ + void tr_rpcSetPassword (tr_rpc_server * server, + const char * password); + +diff --git a/libtransmission/session.c b/libtransmission/session.c +index 844cadba8..58b717913 100644 +--- libtransmission/session.c.orig ++++ libtransmission/session.c +@@ -359,6 +359,8 @@ tr_sessionGetDefaultSettings (tr_variant * d) + tr_variantDictAddStr (d, TR_KEY_rpc_username, ""); + tr_variantDictAddStr (d, TR_KEY_rpc_whitelist, TR_DEFAULT_RPC_WHITELIST); + tr_variantDictAddBool (d, TR_KEY_rpc_whitelist_enabled, true); ++ tr_variantDictAddStr(d, TR_KEY_rpc_host_whitelist, TR_DEFAULT_RPC_HOST_WHITELIST); ++ tr_variantDictAddBool(d, TR_KEY_rpc_host_whitelist_enabled, true); + tr_variantDictAddInt (d, TR_KEY_rpc_port, atoi (TR_DEFAULT_RPC_PORT_STR)); + tr_variantDictAddStr (d, TR_KEY_rpc_url, TR_DEFAULT_RPC_URL_STR); + tr_variantDictAddBool (d, TR_KEY_scrape_paused_torrents_enabled, true); +diff --git a/libtransmission/transmission.h b/libtransmission/transmission.h +index 4f76adfd6..e213a8f4e 100644 +--- libtransmission/transmission.h.orig ++++ libtransmission/transmission.h +@@ -123,6 +123,7 @@ const char* tr_getDefaultDownloadDir (void); + #define TR_DEFAULT_BIND_ADDRESS_IPV4 "0.0.0.0" + #define TR_DEFAULT_BIND_ADDRESS_IPV6 "::" + #define TR_DEFAULT_RPC_WHITELIST "127.0.0.1" ++#define TR_DEFAULT_RPC_HOST_WHITELIST "" + #define TR_DEFAULT_RPC_PORT_STR "9091" + #define TR_DEFAULT_RPC_URL_STR "/transmission/" + #define TR_DEFAULT_PEER_PORT_STR "51413" +diff --git a/libtransmission/web.c b/libtransmission/web.c +index ee495e9fc..c7f062730 100644 +--- libtransmission/web.c.orig ++++ libtransmission/web.c +@@ -594,6 +594,7 @@ tr_webGetResponseStr (long code) + case 415: return "Unsupported Media Type"; + case 416: return "Requested Range Not Satisfiable"; + case 417: return "Expectation Failed"; ++ case 421: return "Misdirected Request"; + case 500: return "Internal Server Error"; + case 501: return "Not Implemented"; + case 502: return "Bad Gateway"; Modified: head/net-p2p/transmission-daemon/Makefile ============================================================================== --- head/net-p2p/transmission-daemon/Makefile Sun Jan 14 22:26:08 2018 (r459010) +++ head/net-p2p/transmission-daemon/Makefile Sun Jan 14 22:35:00 2018 (r459011) @@ -1,6 +1,6 @@ # $FreeBSD$ -PORTREVISION= 3 +PORTREVISION= 4 PKGNAMESUFFIX= -daemon MAINTAINER= crees@FreeBSD.org
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