diff --git a/ChangeLog b/ChangeLog index 0d079c871..b9af47b30 100644 --- a/ChangeLog +++ b/ChangeLog @@ -21,6 +21,8 @@ Security against Bellcore glitch attack. * Fix a buffer overread in ssl_parse_server_key_exchange() that could cause a crash on invalid input. + * Fix a buffer overread in ssl_parse_server_psk_hint() that could cause a + crash on invalid input. Features * Extend PKCS#8 interface by introducing support for the entire SHA @@ -59,6 +61,8 @@ Bugfix parsing the subject alternative names. * Fix a possible arithmetic overflow in ssl_parse_server_key_exchange() that could cause a key exchange to fail on valid data. + * Fix a possible arithmetic overflow in ssl_parse_server_psk_hint() that + could cause a key exchange to fail on valid data. Changes * Fix tag lengths and value ranges in the documentation of CCM encryption. diff --git a/library/ssl_cli.c b/library/ssl_cli.c index fc90f86aa..88864b813 100644 --- a/library/ssl_cli.c +++ b/library/ssl_cli.c @@ -2058,10 +2058,16 @@ static int ssl_parse_server_psk_hint( mbedtls_ssl_context *ssl, * * opaque psk_identity_hint<0..2^16-1>; */ + if( (*p) > end - 2 ) + { + MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message " + "(psk_identity_hint length)" ) ); + return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE ); + } len = (*p)[0] << 8 | (*p)[1]; *p += 2; - if( (*p) + len > end ) + if( (*p) > end - len ) { MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message " "(psk_identity_hint length)" ) );