CVE-2017-13051/RSVP: fix bounds checks for UNI

[tcpdump] / print-tcp.c

diff --git a/print-tcp.c b/print-tcp.c
index 0ed158fa41fe0371c669496c1a24f909279c9713..e0d0531b36b26eed49ff08449cc6c880cb0524e0 100644 (file)
--- a/print-tcp.c
+++ b/print-tcp.c
@@ -129,7 +129,7 @@ static const struct tok tcp_option_values[] = {
         { TCPOPT_SIGNATURE, "md5" },
         { TCPOPT_SCPS, "scps" },
         { TCPOPT_UTO, "uto" },
-        { TCPOPT_AUTH, "enhanced auth" },
+        { TCPOPT_TCPAO, "tcp-ao" },
         { TCPOPT_MPTCP, "mptcp" },
         { TCPOPT_FASTOPEN, "tfo" },
         { TCPOPT_EXPERIMENT2, "exp" },
@@ -544,17 +544,30 @@ tcp_print(netdissect_options *ndo,
                                 ND_PRINT((ndo, " cap %02x id %u", cp[0], cp[1]));
                                 break;
 
-                        case TCPOPT_AUTH:
-                                LENCHECK(1);
-                                ND_PRINT((ndo, " keyid %d", *cp++));
-                                datalen = len - 3;
-                                for (i = 0; i < datalen; ++i) {
-                                        LENCHECK(i + 1);
-                                        ND_PRINT((ndo, "%02x", cp[i]));
+                        case TCPOPT_TCPAO:
+                                datalen = len - 2;
+                                /* RFC 5925 Section 2.2:
+                                 * "The Length value MUST be greater than or equal to 4."
+                                 * (This includes the Kind and Length fields already processed
+                                 * at this point.)
+                                 */
+                                if (datalen < 2) {
+                                        ND_PRINT((ndo, " invalid"));
+                                } else {
+                                        LENCHECK(1);
+                                        ND_PRINT((ndo, " keyid %u", cp[0]));
+                                        LENCHECK(2);
+                                        ND_PRINT((ndo, " rnextkeyid %u", cp[1]));
+                                        if (datalen > 2) {
+                                                ND_PRINT((ndo, " mac 0x"));
+                                                for (i = 2; i < datalen; i++) {
+                                                        LENCHECK(i + 1);
+                                                        ND_PRINT((ndo, "%02x", cp[i]));
+                                                }
+                                        }
                                 }
                                 break;
 
-
                         case TCPOPT_EOL:
                         case TCPOPT_NOP:
                         case TCPOPT_SACKOK: