From: Dr. Stephen Henson <steve@openssl.org>
Date: Thu, 24 Jul 2014 23:50:06 +0000 (+0100)
Subject: Fix SRP ciphersuite DoS vulnerability.
X-Git-Tag: OpenSSL_1_0_2-beta3~113
X-Git-Url: https://git.openssl.org/?p=openssl.git;a=commitdiff_plain;h=f338c2e0c2ce1e89cf8eba2d38878081f46b9dce

Fix SRP ciphersuite DoS vulnerability.

If a client attempted to use an SRP ciphersuite and it had not been
set up correctly it would crash with a null pointer read. A malicious
server could exploit this in a DoS attack.

Thanks to Joonas Kuorilehto and Riku Hietamäki from Codenomicon
for reporting this issue.

CVE-2014-2970
Reviewed-by: Tim Hudson <tjh@openssl.org>
---

diff --git a/ssl/t1_lib.c b/ssl/t1_lib.c
index 9e5927f826..ba2d9ae8f0 100644
--- a/ssl/t1_lib.c
+++ b/ssl/t1_lib.c
@@ -1086,6 +1086,13 @@ void ssl_set_client_disabled(SSL *s)
 		c->mask_k |= SSL_kPSK;
 		}
 #endif /* OPENSSL_NO_PSK */
+#ifndef OPENSSL_NO_SRP
+	if (!(s->srp_ctx.srp_Mask & SSL_kSRP))
+		{
+		c->mask_a |= SSL_aSRP;
+		c->mask_k |= SSL_kSRP;
+		}
+#endif
 	c->valid = 1;
 	}