diff options
| author | Matt Caswell <matt@openssl.org> | 2015-03-10 16:38:32 +0000 |
|---|---|---|
| committer | Matt Caswell <matt@openssl.org> | 2015-03-19 13:01:13 +0000 |
| commit | d3cc5e610d1719a35cda52c9152134b490a8c944 (patch) | |
| tree | e8f888b240b8e2b8e2e5ed013e3c5e1d71c57d8f /ssl | |
| parent | 34e3edbf3a10953cb407288101fd56a629af22f9 (diff) | |
Fix DHE Null CKE vulnerability
If client auth is used then a server can seg fault in the event of a DHE
cipher being used and a zero length ClientKeyExchange message being sent
by the client. This could be exploited in a DoS attack.
CVE-2015-1787
Reviewed-by: Richard Levitte <levitte@openssl.org>
Diffstat (limited to 'ssl')
| -rw-r--r-- | ssl/s3_srvr.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/ssl/s3_srvr.c b/ssl/s3_srvr.c index e5346b6aff..f8c7e373cd 100644 --- a/ssl/s3_srvr.c +++ b/ssl/s3_srvr.c @@ -2233,10 +2233,17 @@ int ssl3_get_client_key_exchange(SSL *s) if (alg_k & (SSL_kDHE | SSL_kDHr | SSL_kDHd)) { int idx = -1; EVP_PKEY *skey = NULL; - if (n) + if (n > 1) { n2s(p, i); - else + } else { + if (alg_k & SSL_kDHE) { + al = SSL_AD_HANDSHAKE_FAILURE; + SSLerr(SSL_F_SSL3_GET_CLIENT_KEY_EXCHANGE, + SSL_R_DH_PUBLIC_VALUE_LENGTH_IS_WRONG); + goto f_err; + } i = 0; + } if (n && n != i + 2) { if (!(s->options & SSL_OP_SSLEAY_080_CLIENT_DH_BUG)) { SSLerr(SSL_F_SSL3_GET_CLIENT_KEY_EXCHANGE, |