diff --git a/ChangeLog b/ChangeLog
index d3b7124..9821551 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -2,6 +2,11 @@
 
 = PolarSSL 1.3.z branch
 
+Security
+   * Fix remotely-triggerable uninitialised pointer dereference caused by
+     crafted X.509 certificate (server is not affected if it doesn't ask for a
+     client certificate) (found using Codenomicon Defensics).
+
 Features
    * Add function pk_check_pair() to test if public and private keys match.
 
diff --git a/library/asn1parse.c b/library/asn1parse.c
index a3a2b56..e2117bf 100644
--- a/library/asn1parse.c
+++ b/library/asn1parse.c
@@ -278,6 +278,8 @@
             if( cur->next == NULL )
                 return( POLARSSL_ERR_ASN1_MALLOC_FAILED );
 
+            memset( cur->next, 0, sizeof( asn1_sequence ) );
+
             cur = cur->next;
         }
     }
diff --git a/tests/suites/test_suite_x509parse.data b/tests/suites/test_suite_x509parse.data
index 4cc924f..c2bb7f3 100644
--- a/tests/suites/test_suite_x509parse.data
+++ b/tests/suites/test_suite_x509parse.data
@@ -869,6 +869,10 @@
 depends_on:POLARSSL_RSA_C
 x509parse_crt:"3081a230819fa0030201028204deadbeef300d06092a864886f70d0101020500300c310a30080600130454657374301c170c303930313031303030303030170c303931323331323335393539300c310a30080600130454657374302a300d06092A864886F70D010101050003190030160210ffffffffffffffffffffffffffffffff0202ffffa101aaa201bba317301530130603551d130101010409300702010102010100":"":POLARSSL_ERR_X509_INVALID_EXTENSIONS + POLARSSL_ERR_ASN1_LENGTH_MISMATCH
 
+X509 Certificate ASN1 (ExtKeyUsage, bad second tag)
+depends_on:POLARSSL_ECP_C:POLARSSL_ECP_DP_SECP256R1_ENABLED
+x509parse_crt:"3081de3081dba003020102020900ebdbcd14105e1839300906072a8648ce3d0401300f310d300b0603550403130454657374301e170d3134313131313230353935345a170d3234313130383230353935345a300f310d300b06035504031304546573743059301306072a8648ce3d020106082a8648ce3d0301070342000437cc56d976091e5a723ec7592dff206eee7cf9069174d0ad14b5f768225962924ee500d82311ffea2fd2345d5d16bd8a88c26b770d55cd8a2a0efa01c8b4edffa321301f301d0603551d250416301406082b0601050507030107082b06010505070302":"":POLARSSL_ERR_X509_INVALID_EXTENSIONS + POLARSSL_ERR_ASN1_UNEXPECTED_TAG
+
 X509 Certificate ASN1 (correct pubkey, no sig_alg)
 depends_on:POLARSSL_RSA_C
 x509parse_crt:"308183308180a0030201008204deadbeef300d06092a864886f70d0101020500300c310a30080600130454657374301c170c303930313031303030303030170c303931323331323335393539300c310a30080600130454657374302a300d06092A864886F70D010101050003190030160210ffffffffffffffffffffffffffffffff0202ffff":"":POLARSSL_ERR_X509_INVALID_ALG + POLARSSL_ERR_ASN1_OUT_OF_DATA