wpa_supplicant : PSK configuration parameter update allowing arbitrary data to be...

This commit is patch for mitigation security vulnerability on wpa_supplicant
 - https://w1.fi/security/2016-1/

    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.

Change-Id: I41f6fed02ed00b0031b25a7e629094509d753675
Signed-off-by: Jin-Seong Kim <jseong82.kim@samsung.com>

diff --git a/external/wpa_supplicant/wpa_supplicant/config.c b/external/wpa_supplicant/wpa_supplicant/config.c
index 905d840..5731825 100644 (file)
--- a/external/wpa_supplicant/wpa_supplicant/config.c
+++ b/external/wpa_supplicant/wpa_supplicant/config.c
@@ -2623,6 +2623,8 @@ int wpa_config_set_cred(struct wpa_cred *cred, const char *var, const char *valu
        }
 
        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;
@@ -2674,8 +2676,13 @@ int wpa_config_set_cred(struct wpa_cred *cred, const char *var, const char *valu
        }
 
        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;
        }