Sanity check record length before skipping explicit IV in TLS 1.2, 1.1 and
DTLS to fix DoS attack.
Thanks to Codenomicon for discovering this issue using Fuzz-o-Matic
fuzzing as a service testing platform.
(CVE-2012-2333)
diff --git a/CHANGES b/CHANGES
index 8425bb3..2656e66 100644
--- a/CHANGES
+++ b/CHANGES
@@ -292,6 +292,14 @@
Changes between 1.0.1b and 1.0.1c [xx XXX xxxx]
+ *) Sanity check record length before skipping explicit IV in TLS
+ 1.2, 1.1 and DTLS to avoid DoS attack.
+
+ Thanks to Codenomicon for discovering this issue using Fuzz-o-Matic
+ fuzzing as a service testing platform.
+ (CVE-2012-2333)
+ [Steve Henson]
+
*) Initialise tkeylen properly when encrypting CMS messages.
Thanks to Solar Designer of Openwall for reporting this issue.
[Steve Henson]
diff --git a/ssl/d1_enc.c b/ssl/d1_enc.c
index becbab9..07a5e97 100644
--- a/ssl/d1_enc.c
+++ b/ssl/d1_enc.c
@@ -260,7 +260,7 @@
}
/* TLS 1.0 does not bound the number of padding bytes by the block size.
* All of them must have value 'padding_length'. */
- if (i > (int)rec->length)
+ if (i + bs > (int)rec->length)
{
/* Incorrect padding. SSLerr() and ssl3_alert are done
* by caller: we don't want to reveal whether this is
diff --git a/ssl/t1_enc.c b/ssl/t1_enc.c
index 201ca9a..f7bdeb3 100644
--- a/ssl/t1_enc.c
+++ b/ssl/t1_enc.c
@@ -889,6 +889,8 @@
if (s->version >= TLS1_1_VERSION
&& EVP_CIPHER_CTX_mode(ds) == EVP_CIPH_CBC_MODE)
{
+ if (bs > (int)rec->length)
+ return -1;
rec->data += bs; /* skip the explicit IV */
rec->input += bs;
rec->length -= bs;
