From: Dr. Stephen Henson <steve@openssl.org>
Date: Wed, 4 Jan 2012 23:16:15 +0000 (+0000)
Subject: Clear bytes used for block padding of SSL 3.0 records. (CVE-2011-4576)
X-Git-Tag: master-post-reformat~2003
X-Git-Url: https://git.openssl.org/?p=openssl.git;a=commitdiff_plain;h=27dfffd5b75ee1db114e32f6dc73e266513889c5

Clear bytes used for block padding of SSL 3.0 records. (CVE-2011-4576)
---

diff --git a/CHANGES b/CHANGES
index 04b14bda8c..176b649453 100644
--- a/CHANGES
+++ b/CHANGES
@@ -523,6 +523,10 @@
 
  Changes between 1.0.0e and 1.0.0f [xx XXX xxxx]
 
+  *) Clear bytes used for block padding of SSL 3.0 records.
+     (CVE-2011-4576)
+     [Adam Langley (Google)]
+
   *) Only allow one SGC handshake restart for SSL/TLS. (CVE-2011-4619)
      [Adam Langley (Google)]
 
diff --git a/ssl/s3_enc.c b/ssl/s3_enc.c
index 0ddfe192bc..c5df2cb90a 100644
--- a/ssl/s3_enc.c
+++ b/ssl/s3_enc.c
@@ -512,6 +512,9 @@ int ssl3_enc(SSL *s, int send)
 
 			/* we need to add 'i-1' padding bytes */
 			l+=i;
+			/* the last of these zero bytes will be overwritten
+			 * with the padding length. */
+			memset(&rec->input[rec->length], 0, i);
 			rec->length+=i;
 			rec->input[l-1]=(i-1);
 			}