From b166cd84a77a6717be9600bf95378a0055d6f5a5 Mon Sep 17 00:00:00 2001 From: Jouni Malinen Date: Tue, 5 Apr 2016 23:33:10 +0300 Subject: [PATCH] Reject SET_CRED commands with newline characters in the string values Most of the cred block parameters are written as strings without filtering and if there is an embedded newline character in the value, unexpected configuration file data might be written. This fixes an issue where wpa_supplicant could have updated the configuration file cred parameter with arbitrary data from the control interface or D-Bus interface. While those interfaces are supposed to be accessible only for trusted users/applications, it may be possible that an untrusted user has access to a management software component that does not validate the credential value before passing it to wpa_supplicant. This could allow such an untrusted user to inject almost arbitrary data into the configuration file. Such configuration file could result in wpa_supplicant trying to load a library (e.g., opensc_engine_path, pkcs11_engine_path, pkcs11_module_path, load_dynamic_eap) from user controlled location when starting again. This would allow code from that library to be executed under the wpa_supplicant process privileges. Signed-off-by: Jouni Malinen Signed-off-by: Baruch Siach --- Patch status: upstream (b166cd84a77a6717be9600bf95378a0055d6f5a5) wpa_supplicant/config.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/wpa_supplicant/config.c b/wpa_supplicant/config.c index eb97cd5e4e6e..69152efdea1a 100644 --- a/wpa_supplicant/config.c +++ b/wpa_supplicant/config.c @@ -2896,6 +2896,8 @@ int wpa_config_set_cred(struct wpa_cred *cred, const char *var, if (os_strcmp(var, "password") == 0 && os_strncmp(value, "ext:", 4) == 0) { + if (has_newline(value)) + return -1; str_clear_free(cred->password); cred->password = os_strdup(value); cred->ext_password = 1; @@ -2946,9 +2948,14 @@ int wpa_config_set_cred(struct wpa_cred *cred, const char *var, } val = wpa_config_parse_string(value, &len); - if (val == NULL) { + if (val == NULL || + (os_strcmp(var, "excluded_ssid") != 0 && + os_strcmp(var, "roaming_consortium") != 0 && + os_strcmp(var, "required_roaming_consortium") != 0 && + has_newline(val))) { wpa_printf(MSG_ERROR, "Line %d: invalid field '%s' string " "value '%s'.", line, var, value); + os_free(val); return -1; } -- 2.8.1