From: Andrew Bartlett Date: Wed, 15 Sep 2021 20:46:42 +0000 (+1200) Subject: CVE-2020-25722 dsdb: objectclass computer becomes UF_WORKSTATION_TRUST by default X-Git-Tag: samba-4.13.14~205 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e3021debe82e6a35f128eb600bc11df40c441a98;p=thirdparty%2Fsamba.git CVE-2020-25722 dsdb: objectclass computer becomes UF_WORKSTATION_TRUST by default There are a lot of knownfail entries added with this commit. These all need to be addressed and removed in subsequent commits which will restructure the tests to pass within this new reality. This default applies even to users with administrator rights, as changing the default based on permissions would break to many assumptions. BUG: https://bugzilla.samba.org/show_bug.cgi?id=14753 Signed-off-by: Andrew Bartlett Reviewed-by: Douglas Bagnall --- diff --git a/selftest/knownfail.d/uac_objectclass_restrict b/selftest/knownfail.d/uac_objectclass_restrict new file mode 100644 index 00000000000..a076f9cfedb --- /dev/null +++ b/selftest/knownfail.d/uac_objectclass_restrict @@ -0,0 +1,42 @@ +# Knownfail entries due to restricting the creation of computer/user +# accounts (in terms of userAccountControl) that do not match the objectclass +# +# All these tests need to be fixed and the entries here removed + +^samba4.sam.python\(fl2008r2dc\).__main__.SamTests.test_isCriticalSystemObject\(fl2008r2dc\) +^samba4.sam.python\(fl2008r2dc\).__main__.SamTests.test_userAccountControl\(fl2008r2dc\) +^samba4.sam.python\(fl2008r2dc\).__main__.SamTests.test_users_groups\(fl2008r2dc\) +^samba4.ldap.python\(ad_dc_default\).__main__.BasicTests.test_all\(ad_dc_default\) +^samba4.sam.python\(ad_dc_default\).__main__.SamTests.test_isCriticalSystemObject\(ad_dc_default\) +^samba4.sam.python\(ad_dc_default\).__main__.SamTests.test_userAccountControl\(ad_dc_default\) +^samba4.sam.python\(ad_dc_default\).__main__.SamTests.test_users_groups\(ad_dc_default\) +^samba4.user_account_control.python\(ad_dc_default\).__main__.UserAccountControlTests.test_add_computer_sd_cc\(ad_dc_default\) +^samba4.user_account_control.python\(ad_dc_default\).__main__.UserAccountControlTests.test_admin_mod_uac\(ad_dc_default\) +^samba4.user_account_control.python\(ad_dc_default\).__main__.UserAccountControlTests.test_mod_computer_cc\(ad_dc_default\) +^samba4.user_account_control.python\(ad_dc_default\).__main__.UserAccountControlTests.test_uac_bits_set_0x10000000\(ad_dc_default\) +^samba4.user_account_control.python\(ad_dc_default\).__main__.UserAccountControlTests.test_uac_bits_set_0x20000000\(ad_dc_default\) +^samba4.user_account_control.python\(ad_dc_default\).__main__.UserAccountControlTests.test_uac_bits_set_0x40000000\(ad_dc_default\) +^samba4.user_account_control.python\(ad_dc_default\).__main__.UserAccountControlTests.test_uac_bits_set_0x80000000\(ad_dc_default\) +^samba4.user_account_control.python\(ad_dc_default\).__main__.UserAccountControlTests.test_uac_bits_set_UF_00000004\(ad_dc_default\) +^samba4.user_account_control.python\(ad_dc_default\).__main__.UserAccountControlTests.test_uac_bits_set_UF_00000400\(ad_dc_default\) +^samba4.user_account_control.python\(ad_dc_default\).__main__.UserAccountControlTests.test_uac_bits_set_UF_00004000\(ad_dc_default\) +^samba4.user_account_control.python\(ad_dc_default\).__main__.UserAccountControlTests.test_uac_bits_set_UF_00008000\(ad_dc_default\) +^samba4.user_account_control.python\(ad_dc_default\).__main__.UserAccountControlTests.test_uac_bits_set_UF_ACCOUNTDISABLE\(ad_dc_default\) +^samba4.user_account_control.python\(ad_dc_default\).__main__.UserAccountControlTests.test_uac_bits_set_UF_DONT_EXPIRE_PASSWD\(ad_dc_default\) +^samba4.user_account_control.python\(ad_dc_default\).__main__.UserAccountControlTests.test_uac_bits_set_UF_DONT_REQUIRE_PREAUTH\(ad_dc_default\) +^samba4.user_account_control.python\(ad_dc_default\).__main__.UserAccountControlTests.test_uac_bits_set_UF_ENCRYPTED_TEXT_PASSWORD_ALLOWED\(ad_dc_default\) +^samba4.user_account_control.python\(ad_dc_default\).__main__.UserAccountControlTests.test_uac_bits_set_UF_HOMEDIR_REQUIRED\(ad_dc_default\) +^samba4.user_account_control.python\(ad_dc_default\).__main__.UserAccountControlTests.test_uac_bits_set_UF_LOCKOUT\(ad_dc_default\) +^samba4.user_account_control.python\(ad_dc_default\).__main__.UserAccountControlTests.test_uac_bits_set_UF_MNS_LOGON_ACCOUNT\(ad_dc_default\) +^samba4.user_account_control.python\(ad_dc_default\).__main__.UserAccountControlTests.test_uac_bits_set_UF_NORMAL_ACCOUNT\(ad_dc_default\) +^samba4.user_account_control.python\(ad_dc_default\).__main__.UserAccountControlTests.test_uac_bits_set_UF_NOT_DELEGATED\(ad_dc_default\) +^samba4.user_account_control.python\(ad_dc_default\).__main__.UserAccountControlTests.test_uac_bits_set_UF_NO_AUTH_DATA_REQUIRED\(ad_dc_default\) +^samba4.user_account_control.python\(ad_dc_default\).__main__.UserAccountControlTests.test_uac_bits_set_UF_PASSWD_CANT_CHANGE\(ad_dc_default\) +^samba4.user_account_control.python\(ad_dc_default\).__main__.UserAccountControlTests.test_uac_bits_set_UF_PASSWD_NOTREQD\(ad_dc_default\) +^samba4.user_account_control.python\(ad_dc_default\).__main__.UserAccountControlTests.test_uac_bits_set_UF_PASSWORD_EXPIRED\(ad_dc_default\) +^samba4.user_account_control.python\(ad_dc_default\).__main__.UserAccountControlTests.test_uac_bits_set_UF_SCRIPT\(ad_dc_default\) +^samba4.user_account_control.python\(ad_dc_default\).__main__.UserAccountControlTests.test_uac_bits_set_UF_SMARTCARD_REQUIRED\(ad_dc_default\) +^samba4.user_account_control.python\(ad_dc_default\).__main__.UserAccountControlTests.test_uac_bits_set_UF_USE_AES_KEYS\(ad_dc_default\) +^samba4.user_account_control.python\(ad_dc_default\).__main__.UserAccountControlTests.test_uac_bits_set_UF_USE_DES_KEY_ONLY\(ad_dc_default\) +^samba4.user_account_control.python\(ad_dc_default\).__main__.UserAccountControlTests.test_uac_bits_set_UF_WORKSTATION_TRUST_ACCOUNT\(ad_dc_default\) +^samba4.user_account_control.python\(ad_dc_default\).__main__.UserAccountControlTests.test_uac_bits_unrelated_modify_UF_NORMAL_ACCOUNT\(ad_dc_default\) diff --git a/source4/dsdb/samdb/ldb_modules/samldb.c b/source4/dsdb/samdb/ldb_modules/samldb.c index cb5fda324a4..8df86f29883 100644 --- a/source4/dsdb/samdb/ldb_modules/samldb.c +++ b/source4/dsdb/samdb/ldb_modules/samldb.c @@ -1413,19 +1413,33 @@ static int samldb_objectclass_trigger(struct samldb_ctx *ac) switch(ac->type) { case SAMLDB_TYPE_USER: { + bool is_computer_objectclass; bool uac_generated = false, uac_add_flags = false; - + uint32_t default_user_account_control = UF_NORMAL_ACCOUNT; /* Step 1.2: Default values */ ret = dsdb_user_obj_set_defaults(ldb, ac->msg, ac->req); if (ret != LDB_SUCCESS) return ret; + is_computer_objectclass + = (samdb_find_attribute(ldb, + ac->msg, + "objectclass", + "computer") + != NULL); + + if (is_computer_objectclass) { + default_user_account_control + = UF_WORKSTATION_TRUST_ACCOUNT; + } + + /* On add operations we might need to generate a * "userAccountControl" (if it isn't specified). */ el = ldb_msg_find_element(ac->msg, "userAccountControl"); if ((el == NULL) && (ac->req->operation == LDB_ADD)) { ret = samdb_msg_set_uint(ldb, ac->msg, ac->msg, "userAccountControl", - UF_NORMAL_ACCOUNT); + default_user_account_control); if (ret != LDB_SUCCESS) { return ret; } @@ -1444,11 +1458,14 @@ static int samldb_objectclass_trigger(struct samldb_ctx *ac) raw_uac = user_account_control; /* * "userAccountControl" = 0 or missing one of - * the types means "UF_NORMAL_ACCOUNT". See - * MS-SAMR 3.1.1.8.10 point 8 + * the types means "UF_NORMAL_ACCOUNT" + * or "UF_WORKSTATION_TRUST_ACCOUNT" (if a computer). + * See MS-SAMR 3.1.1.8.10 point 8 */ if ((user_account_control & UF_ACCOUNT_TYPE_MASK) == 0) { - user_account_control = UF_NORMAL_ACCOUNT | user_account_control; + user_account_control + = default_user_account_control + | user_account_control; uac_generated = true; }