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WPA: Discard EAPOL-Key msg 1/4 with corrupted information elements

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Currently a corrupted handshake message 1/4 causes the client to
disconnect from the network. This can lead to a denial-of-service
vulnerability allowing an adversary to forcibly disconnect a client from
protected networks even when Wi-Fi Management Frame Protection (MFP) is
enforced if the driver allows unencrypted EAPOL-Key frames to be
received after key configuration..

Fix this by discarding the corrupted handshake message 1/4.

This issue was discovered by Domien Schepers (Northeastern University)
and Mathy Vanhoef (imec-DistriNet, KU Leuven).

Signed-off-by: Domien Schepers <schepers.d@northeastern.edu>
This commit is contained in:
Domien Schepers 2022-05-05 21:53:26 +02:00 • committed by Jouni Malinen
parent f8967ece23
commit b1172c19e1
1 changed files with 7 additions and 3 deletions
Download patch file Download diff file Expand all files Collapse all files

10
src/rsn_supp/wpa.c
View file

@ -694,7 +694,6 @@ static void wpa_supplicant_process_1_of_4(struct wpa_sm *sm,
return; return;
} }
wpa_sm_set_state(sm, WPA_4WAY_HANDSHAKE);
wpa_dbg(sm->ctx->msg_ctx, MSG_DEBUG, "WPA: RX message 1 of 4-Way " wpa_dbg(sm->ctx->msg_ctx, MSG_DEBUG, "WPA: RX message 1 of 4-Way "
"Handshake from " MACSTR " (ver=%d)", MAC2STR(src_addr), ver); "Handshake from " MACSTR " (ver=%d)", MAC2STR(src_addr), ver);
@ -704,8 +703,11 @@ static void wpa_supplicant_process_1_of_4(struct wpa_sm *sm,
/* RSN: msg 1/4 should contain PMKID for the selected PMK */ /* RSN: msg 1/4 should contain PMKID for the selected PMK */
wpa_hexdump(MSG_DEBUG, "RSN: msg 1/4 key data", wpa_hexdump(MSG_DEBUG, "RSN: msg 1/4 key data",
key_data, key_data_len); key_data, key_data_len);
if (wpa_supplicant_parse_ies(key_data, key_data_len, &ie) < 0) if (wpa_supplicant_parse_ies(key_data, key_data_len, &ie) < 0) {
goto failed; wpa_printf(MSG_DEBUG,
"RSN: Discard EAPOL-Key msg 1/4 with invalid IEs/KDEs");
return;
}
if (ie.pmkid) { if (ie.pmkid) {
wpa_hexdump(MSG_DEBUG, "RSN: PMKID from " wpa_hexdump(MSG_DEBUG, "RSN: PMKID from "
"Authenticator", ie.pmkid, PMKID_LEN); "Authenticator", ie.pmkid, PMKID_LEN);
@ -721,6 +723,8 @@ static void wpa_supplicant_process_1_of_4(struct wpa_sm *sm,
if (res) if (res)
goto failed; goto failed;
wpa_sm_set_state(sm, WPA_4WAY_HANDSHAKE);
if (sm->renew_snonce) { if (sm->renew_snonce) {
if (random_get_bytes(sm->snonce, WPA_NONCE_LEN)) { if (random_get_bytes(sm->snonce, WPA_NONCE_LEN)) {
wpa_msg(sm->ctx->msg_ctx, MSG_WARNING, wpa_msg(sm->ctx->msg_ctx, MSG_WARNING,