wpa-supplicant: fix CVE-2018-14526

Ignore unauthenticated encrypted EAPOL-Key data in supplicant
processing. When using WPA2, these are frames that have the Encrypted
flag set, but not the MIC flag.

(From OE-Core rev: a5a07887e73ebf0aa6b3b1fa247e44743b39322e)

Signed-off-by: Andrej Valek <andrej.valek@siemens.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

2 files changed, 45 insertions, 0 deletions

diff --git a/meta/recipes-connectivity/wpa-supplicant/wpa-supplicant/wpa_supplicant-CVE-2018-14526.patch b/meta/recipes-connectivity/wpa-supplicant/wpa-supplicant/wpa_supplicant-CVE-2018-14526.patch
new file mode 100644
index 0000000000..e800a410ea
--- /dev/null
+++ b/meta/recipes-connectivity/wpa-supplicant/wpa-supplicant/wpa_supplicant-CVE-2018-14526.patch
@@ -0,0 +1,44 @@
+wpa_supplicant-2.6: Fix CVE-2018-14526
+
+[No upstream tracking] -- https://w1.fi/security/2018-1/unauthenticated-eapol-key-decryption.txt
+
+wpa: Ignore unauthenticated encrypted EAPOL-Key data
+
+Ignore unauthenticated encrypted EAPOL-Key data in supplicant
+processing. When using WPA2, these are frames that have the Encrypted
+flag set, but not the MIC flag.
+
+When using WPA2, EAPOL-Key frames that had the Encrypted flag set but
+not the MIC flag, had their data field decrypted without first verifying
+the MIC. In case the data field was encrypted using RC4 (i.e., when
+negotiating TKIP as the pairwise cipher), this meant that
+unauthenticated but decrypted data would then be processed. An adversary
+could abuse this as a decryption oracle to recover sensitive information
+in the data field of EAPOL-Key messages (e.g., the group key).
+
+Upstream-Status: Backport [https://w1.fi/cgit/hostap/commit/src/rsn_supp/wpa.c?id=3e34cfdff6b192fe337c6fb3f487f73e96582961]
+CVE: CVE-2018-14526
+Signed-off-by: Andrej Valek <andrej.valek@siemens.com>
+
+diff --git a/src/rsn_supp/wpa.c b/src/rsn_supp/wpa.c
+index 3c47879..6bdf923 100644
+--- a/src/rsn_supp/wpa.c
++++ b/src/rsn_supp/wpa.c
+@@ -2016,6 +2016,17 @@ int wpa_sm_rx_eapol(struct wpa_sm *sm, const u8 *src_addr,
+
+        if ((sm->proto == WPA_PROTO_RSN || sm->proto == WPA_PROTO_OSEN) &&
+            (key_info & WPA_KEY_INFO_ENCR_KEY_DATA)) {
++               /*
++                * Only decrypt the Key Data field if the frame's authenticity
++                * was verified. When using AES-SIV (FILS), the MIC flag is not
++                * set, so this check should only be performed if mic_len != 0
++                * which is the case in this code branch.
++                */
++               if (!(key_info & WPA_KEY_INFO_MIC)) {
++                       wpa_msg(sm->ctx->msg_ctx, MSG_WARNING,
++                               "WPA: Ignore EAPOL-Key with encrypted but unauthenticated data");
++                       goto out;
++               }
+                if (wpa_supplicant_decrypt_key_data(sm, key, ver, key_data,
+                                                    &key_data_len))
+                        goto out;
diff --git a/meta/recipes-connectivity/wpa-supplicant/wpa-supplicant_2.6.bb b/meta/recipes-connectivity/wpa-supplicant/wpa-supplicant_2.6.bb
index e684537486..aa4c4c2da0 100644
--- a/meta/recipes-connectivity/wpa-supplicant/wpa-supplicant_2.6.bb
+++ b/meta/recipes-connectivity/wpa-supplicant/wpa-supplicant_2.6.bb
@@ -32,6 +32,7 @@ SRC_URI = "http://w1.fi/releases/wpa_supplicant-${PV}.tar.gz  \
            file://key-replay-cve-multiple6.patch \
            file://key-replay-cve-multiple7.patch \
            file://key-replay-cve-multiple8.patch \
+           file://wpa_supplicant-CVE-2018-14526.patch \
           "
 SRC_URI[md5sum] = "091569eb4440b7d7f2b4276dbfc03c3c"
 SRC_URI[sha256sum] = "b4936d34c4e6cdd44954beba74296d964bc2c9668ecaa5255e499636fe2b1450"