Andrew Geissler | 475cb72 | 2020-07-10 16:00:51 -0500 | [diff] [blame] | 1 | From 5b78c8f961f25f4dc22d6f2b77ddd06d712cec63 Mon Sep 17 00:00:00 2001 |
| 2 | From: Jouni Malinen <jouni@codeaurora.org> |
| 3 | Date: Wed, 3 Jun 2020 23:17:35 +0300 |
| 4 | Subject: [PATCH 1/3] WPS UPnP: Do not allow event subscriptions with URLs to |
| 5 | other networks |
| 6 | |
| 7 | The UPnP Device Architecture 2.0 specification errata ("UDA errata |
| 8 | 16-04-2020.docx") addresses a problem with notifications being allowed |
| 9 | to go out to other domains by disallowing such cases. Do such filtering |
| 10 | for the notification callback URLs to avoid undesired connections to |
| 11 | external networks based on subscriptions that any device in the local |
| 12 | network could request when WPS support for external registrars is |
| 13 | enabled (the upnp_iface parameter in hostapd configuration). |
| 14 | |
| 15 | Upstream-Status: Backport |
| 16 | CVE: CVE-2020-12695 patch #1 |
| 17 | Signed-off-by: Jouni Malinen <jouni@codeaurora.org> |
| 18 | Signed-off-by: Armin Kuster <akuster@mvista.com> |
| 19 | |
| 20 | --- |
| 21 | src/wps/wps_er.c | 2 +- |
| 22 | src/wps/wps_upnp.c | 38 ++++++++++++++++++++++++++++++++++++-- |
| 23 | src/wps/wps_upnp_i.h | 3 ++- |
| 24 | 3 files changed, 39 insertions(+), 4 deletions(-) |
| 25 | |
| 26 | Index: wpa_supplicant-2.9/src/wps/wps_er.c |
| 27 | =================================================================== |
| 28 | --- wpa_supplicant-2.9.orig/src/wps/wps_er.c |
| 29 | +++ wpa_supplicant-2.9/src/wps/wps_er.c |
| 30 | @@ -1298,7 +1298,7 @@ wps_er_init(struct wps_context *wps, con |
| 31 | "with %s", filter); |
| 32 | } |
| 33 | if (get_netif_info(er->ifname, &er->ip_addr, &er->ip_addr_text, |
| 34 | - er->mac_addr)) { |
| 35 | + NULL, er->mac_addr)) { |
| 36 | wpa_printf(MSG_INFO, "WPS UPnP: Could not get IP/MAC address " |
| 37 | "for %s. Does it have IP address?", er->ifname); |
| 38 | wps_er_deinit(er, NULL, NULL); |
| 39 | Index: wpa_supplicant-2.9/src/wps/wps_upnp.c |
| 40 | =================================================================== |
| 41 | --- wpa_supplicant-2.9.orig/src/wps/wps_upnp.c |
| 42 | +++ wpa_supplicant-2.9/src/wps/wps_upnp.c |
| 43 | @@ -303,6 +303,14 @@ static void subscr_addr_free_all(struct |
| 44 | } |
| 45 | |
| 46 | |
| 47 | +static int local_network_addr(struct upnp_wps_device_sm *sm, |
| 48 | + struct sockaddr_in *addr) |
| 49 | +{ |
| 50 | + return (addr->sin_addr.s_addr & sm->netmask.s_addr) == |
| 51 | + (sm->ip_addr & sm->netmask.s_addr); |
| 52 | +} |
| 53 | + |
| 54 | + |
| 55 | /* subscr_addr_add_url -- add address(es) for one url to subscription */ |
| 56 | static void subscr_addr_add_url(struct subscription *s, const char *url, |
| 57 | size_t url_len) |
| 58 | @@ -381,6 +389,7 @@ static void subscr_addr_add_url(struct s |
| 59 | |
| 60 | for (rp = result; rp; rp = rp->ai_next) { |
| 61 | struct subscr_addr *a; |
| 62 | + struct sockaddr_in *addr = (struct sockaddr_in *) rp->ai_addr; |
| 63 | |
| 64 | /* Limit no. of address to avoid denial of service attack */ |
| 65 | if (dl_list_len(&s->addr_list) >= MAX_ADDR_PER_SUBSCRIPTION) { |
| 66 | @@ -389,6 +398,13 @@ static void subscr_addr_add_url(struct s |
| 67 | break; |
| 68 | } |
| 69 | |
| 70 | + if (!local_network_addr(s->sm, addr)) { |
| 71 | + wpa_printf(MSG_INFO, |
| 72 | + "WPS UPnP: Ignore a delivery URL that points to another network %s", |
| 73 | + inet_ntoa(addr->sin_addr)); |
| 74 | + continue; |
| 75 | + } |
| 76 | + |
| 77 | a = os_zalloc(sizeof(*a) + alloc_len); |
| 78 | if (a == NULL) |
| 79 | break; |
| 80 | @@ -889,11 +905,12 @@ static int eth_get(const char *device, u |
| 81 | * @net_if: Selected network interface name |
| 82 | * @ip_addr: Buffer for returning IP address in network byte order |
| 83 | * @ip_addr_text: Buffer for returning a pointer to allocated IP address text |
| 84 | + * @netmask: Buffer for returning netmask or %NULL if not needed |
| 85 | * @mac: Buffer for returning MAC address |
| 86 | * Returns: 0 on success, -1 on failure |
| 87 | */ |
| 88 | int get_netif_info(const char *net_if, unsigned *ip_addr, char **ip_addr_text, |
| 89 | - u8 mac[ETH_ALEN]) |
| 90 | + struct in_addr *netmask, u8 mac[ETH_ALEN]) |
| 91 | { |
| 92 | struct ifreq req; |
| 93 | int sock = -1; |
| 94 | @@ -919,6 +936,19 @@ int get_netif_info(const char *net_if, u |
| 95 | in_addr.s_addr = *ip_addr; |
| 96 | os_snprintf(*ip_addr_text, 16, "%s", inet_ntoa(in_addr)); |
| 97 | |
| 98 | + if (netmask) { |
| 99 | + os_memset(&req, 0, sizeof(req)); |
| 100 | + os_strlcpy(req.ifr_name, net_if, sizeof(req.ifr_name)); |
| 101 | + if (ioctl(sock, SIOCGIFNETMASK, &req) < 0) { |
| 102 | + wpa_printf(MSG_ERROR, |
| 103 | + "WPS UPnP: SIOCGIFNETMASK failed: %d (%s)", |
| 104 | + errno, strerror(errno)); |
| 105 | + goto fail; |
| 106 | + } |
| 107 | + addr = (struct sockaddr_in *) &req.ifr_netmask; |
| 108 | + netmask->s_addr = addr->sin_addr.s_addr; |
| 109 | + } |
| 110 | + |
| 111 | #ifdef __linux__ |
| 112 | os_strlcpy(req.ifr_name, net_if, sizeof(req.ifr_name)); |
| 113 | if (ioctl(sock, SIOCGIFHWADDR, &req) < 0) { |
| 114 | @@ -1025,11 +1055,15 @@ static int upnp_wps_device_start(struct |
| 115 | |
| 116 | /* Determine which IP and mac address we're using */ |
| 117 | if (get_netif_info(net_if, &sm->ip_addr, &sm->ip_addr_text, |
| 118 | - sm->mac_addr)) { |
| 119 | + &sm->netmask, sm->mac_addr)) { |
| 120 | wpa_printf(MSG_INFO, "WPS UPnP: Could not get IP/MAC address " |
| 121 | "for %s. Does it have IP address?", net_if); |
| 122 | goto fail; |
| 123 | } |
| 124 | + wpa_printf(MSG_DEBUG, "WPS UPnP: Local IP address %s netmask %s hwaddr " |
| 125 | + MACSTR, |
| 126 | + sm->ip_addr_text, inet_ntoa(sm->netmask), |
| 127 | + MAC2STR(sm->mac_addr)); |
| 128 | |
| 129 | /* Listen for incoming TCP connections so that others |
| 130 | * can fetch our "xml files" from us. |
| 131 | Index: wpa_supplicant-2.9/src/wps/wps_upnp_i.h |
| 132 | =================================================================== |
| 133 | --- wpa_supplicant-2.9.orig/src/wps/wps_upnp_i.h |
| 134 | +++ wpa_supplicant-2.9/src/wps/wps_upnp_i.h |
| 135 | @@ -128,6 +128,7 @@ struct upnp_wps_device_sm { |
| 136 | u8 mac_addr[ETH_ALEN]; /* mac addr of network i.f. we use */ |
| 137 | char *ip_addr_text; /* IP address of network i.f. we use */ |
| 138 | unsigned ip_addr; /* IP address of network i.f. we use (host order) */ |
| 139 | + struct in_addr netmask; |
| 140 | int multicast_sd; /* send multicast messages over this socket */ |
| 141 | int ssdp_sd; /* receive discovery UPD packets on socket */ |
| 142 | int ssdp_sd_registered; /* nonzero if we must unregister */ |
| 143 | @@ -158,7 +159,7 @@ struct subscription * subscription_find( |
| 144 | const u8 uuid[UUID_LEN]); |
| 145 | void subscr_addr_delete(struct subscr_addr *a); |
| 146 | int get_netif_info(const char *net_if, unsigned *ip_addr, char **ip_addr_text, |
| 147 | - u8 mac[ETH_ALEN]); |
| 148 | + struct in_addr *netmask, u8 mac[ETH_ALEN]); |
| 149 | |
| 150 | /* wps_upnp_ssdp.c */ |
| 151 | void msearchreply_state_machine_stop(struct advertisement_state_machine *a); |