diff options
| author | Dr. Stephen Henson <steve@openssl.org> | 2014-04-06 00:51:06 +0100 |
|---|---|---|
| committer | Dr. Stephen Henson <steve@openssl.org> | 2014-04-07 17:53:31 +0100 |
| commit | 96db9023b881d7cd9f379b0c154650d6c108e9a3 (patch) | |
| tree | 68130b178f4f957d1505b5cd666ee51b1254c36a /ssl/d1_both.c | |
| parent | 0d7717fc9c83dafab8153cbd5e2180e6e04cc802 (diff) | |
Add heartbeat extension bounds check.
A missing bounds check in the handling of the TLS heartbeat extension
can be used to reveal up to 64k of memory to a connected client or
server.
Thanks for Neel Mehta of Google Security for discovering this bug and to
Adam Langley <agl@chromium.org> and Bodo Moeller <bmoeller@acm.org> for
preparing the fix (CVE-2014-0160)
Diffstat (limited to 'ssl/d1_both.c')
| -rw-r--r-- | ssl/d1_both.c | 26 |
1 files changed, 18 insertions, 8 deletions
diff --git a/ssl/d1_both.c b/ssl/d1_both.c index 7a5596a6b3..2e8cf681ed 100644 --- a/ssl/d1_both.c +++ b/ssl/d1_both.c @@ -1459,26 +1459,36 @@ dtls1_process_heartbeat(SSL *s) unsigned int payload; unsigned int padding = 16; /* Use minimum padding */ - /* Read type and payload length first */ - hbtype = *p++; - n2s(p, payload); - pl = p; - if (s->msg_callback) s->msg_callback(0, s->version, TLS1_RT_HEARTBEAT, &s->s3->rrec.data[0], s->s3->rrec.length, s, s->msg_callback_arg); + /* Read type and payload length first */ + if (1 + 2 + 16 > s->s3->rrec.length) + return 0; /* silently discard */ + hbtype = *p++; + n2s(p, payload); + if (1 + 2 + payload + 16 > s->s3->rrec.length) + return 0; /* silently discard per RFC 6520 sec. 4 */ + pl = p; + if (hbtype == TLS1_HB_REQUEST) { unsigned char *buffer, *bp; + unsigned int write_length = 1 /* heartbeat type */ + + 2 /* heartbeat length */ + + payload + padding; int r; + if (write_length > SSL3_RT_MAX_PLAIN_LENGTH) + return 0; + /* Allocate memory for the response, size is 1 byte * message type, plus 2 bytes payload length, plus * payload, plus padding */ - buffer = OPENSSL_malloc(1 + 2 + payload + padding); + buffer = OPENSSL_malloc(write_length); bp = buffer; /* Enter response type, length and copy payload */ @@ -1489,11 +1499,11 @@ dtls1_process_heartbeat(SSL *s) /* Random padding */ RAND_pseudo_bytes(bp, padding); - r = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buffer, 3 + payload + padding); + r = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buffer, write_length); if (r >= 0 && s->msg_callback) s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT, - buffer, 3 + payload + padding, + buffer, write_length, s, s->msg_callback_arg); OPENSSL_free(buffer); |