From 07df3dfa6bf081c3f2ad7777995325d834ad3129 Mon Sep 17 00:00:00 2001 From: Jeremy Allison Date: Mon, 5 Aug 2019 13:39:53 -0700 Subject: [PATCH 1/6] CVE-2019-10218 - s3: libsmb: Protect SMB1 client code from evil server returned names. Disconnect with NT_STATUS_INVALID_NETWORK_RESPONSE if so. BUG: https://bugzilla.samba.org/show_bug.cgi?id=14071 Signed-off-by: Jeremy Allison --- source3/libsmb/clilist.c | 75 ++++++++++++++++++++++++++++++++++++++++ source3/libsmb/proto.h | 3 ++ 2 files changed, 78 insertions(+) diff --git a/source3/libsmb/clilist.c b/source3/libsmb/clilist.c index 5cb1fce4338..4f518339e2b 100644 --- a/source3/libsmb/clilist.c +++ b/source3/libsmb/clilist.c @@ -24,6 +24,66 @@ #include "trans2.h" #include "../libcli/smb/smbXcli_base.h" +/**************************************************************************** + Check if a returned directory name is safe. +****************************************************************************/ + +static NTSTATUS is_bad_name(bool windows_names, const char *name) +{ + const char *bad_name_p = NULL; + + bad_name_p = strchr(name, '/'); + if (bad_name_p != NULL) { + /* + * Windows and POSIX names can't have '/'. + * Server is attacking us. + */ + return NT_STATUS_INVALID_NETWORK_RESPONSE; + } + if (windows_names) { + bad_name_p = strchr(name, '\\'); + if (bad_name_p != NULL) { + /* + * Windows names can't have '\\'. + * Server is attacking us. + */ + return NT_STATUS_INVALID_NETWORK_RESPONSE; + } + } + return NT_STATUS_OK; +} + +/**************************************************************************** + Check if a returned directory name is safe. Disconnect if server is + sending bad names. +****************************************************************************/ + +NTSTATUS is_bad_finfo_name(const struct cli_state *cli, + const struct file_info *finfo) +{ + NTSTATUS status = NT_STATUS_OK; + bool windows_names = true; + + if (cli->requested_posix_capabilities & CIFS_UNIX_POSIX_PATHNAMES_CAP) { + windows_names = false; + } + if (finfo->name != NULL) { + status = is_bad_name(windows_names, finfo->name); + if (!NT_STATUS_IS_OK(status)) { + DBG_ERR("bad finfo->name\n"); + return status; + } + } + if (finfo->short_name != NULL) { + status = is_bad_name(windows_names, finfo->short_name); + if (!NT_STATUS_IS_OK(status)) { + DBG_ERR("bad finfo->short_name\n"); + return status; + } + } + return NT_STATUS_OK; +} + /**************************************************************************** Calculate a safe next_entry_offset. ****************************************************************************/ @@ -492,6 +552,13 @@ static NTSTATUS cli_list_old_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx, TALLOC_FREE(finfo); return NT_STATUS_NO_MEMORY; } + + status = is_bad_finfo_name(state->cli, finfo); + if (!NT_STATUS_IS_OK(status)) { + smbXcli_conn_disconnect(state->cli->conn, status); + TALLOC_FREE(finfo); + return status; + } } *pfinfo = finfo; return NT_STATUS_OK; @@ -727,6 +794,14 @@ static void cli_list_trans_done(struct tevent_req *subreq) ff_eos = true; break; } + + status = is_bad_finfo_name(state->cli, finfo); + if (!NT_STATUS_IS_OK(status)) { + smbXcli_conn_disconnect(state->cli->conn, status); + tevent_req_nterror(req, status); + return; + } + if (!state->first && (state->mask[0] != '\0') && strcsequal(finfo->name, state->mask)) { DEBUG(1, ("Error: Looping in FIND_NEXT as name %s has " diff --git a/source3/libsmb/proto.h b/source3/libsmb/proto.h index 6a647da58c8..48855d7112c 100644 --- a/source3/libsmb/proto.h +++ b/source3/libsmb/proto.h @@ -760,6 +760,9 @@ NTSTATUS cli_posix_whoami(struct cli_state *cli, /* The following definitions come from libsmb/clilist.c */ +NTSTATUS is_bad_finfo_name(const struct cli_state *cli, + const struct file_info *finfo); + NTSTATUS cli_list_old(struct cli_state *cli,const char *Mask,uint16_t attribute, NTSTATUS (*fn)(const char *, struct file_info *, const char *, void *), void *state); -- 2.17.1 From 914c985e66adc63d54b3e17dab324f376f84e349 Mon Sep 17 00:00:00 2001 From: Jeremy Allison Date: Tue, 6 Aug 2019 12:08:09 -0700 Subject: [PATCH 2/6] CVE-2019-10218 - s3: libsmb: Protect SMB2 client code from evil server returned names. Disconnect with NT_STATUS_INVALID_NETWORK_RESPONSE if so. BUG: https://bugzilla.samba.org/show_bug.cgi?id=14071 Signed-off-by: Jeremy Allison --- source3/libsmb/cli_smb2_fnum.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/source3/libsmb/cli_smb2_fnum.c b/source3/libsmb/cli_smb2_fnum.c index 535beaab841..3fa322c243b 100644 --- a/source3/libsmb/cli_smb2_fnum.c +++ b/source3/libsmb/cli_smb2_fnum.c @@ -1442,6 +1442,13 @@ NTSTATUS cli_smb2_list(struct cli_state *cli, goto fail; } + /* Protect against server attack. */ + status = is_bad_finfo_name(cli, finfo); + if (!NT_STATUS_IS_OK(status)) { + smbXcli_conn_disconnect(cli->conn, status); + goto fail; + } + if (dir_check_ftype((uint32_t)finfo->mode, (uint32_t)attribute)) { /* -- 2.17.1 From e0e8830b88e45e3e954b1e5074cef8c8bf5406a8 Mon Sep 17 00:00:00 2001 From: Andrew Bartlett Date: Thu, 19 Sep 2019 11:50:01 +1200 Subject: [PATCH 3/6] CVE-2019-14833: Use utf8 characters in the unacceptable password This shows that the "check password script" handling has a bug. BUG: https://bugzilla.samba.org/show_bug.cgi?id=12438 Signed-off-by: Andrew Bartlett --- selftest/knownfail.d/unacceptable-passwords | 1 + selftest/target/Samba4.pm | 2 +- 2 files changed, 2 insertions(+), 1 deletion(-) create mode 100644 selftest/knownfail.d/unacceptable-passwords diff --git a/selftest/knownfail.d/unacceptable-passwords b/selftest/knownfail.d/unacceptable-passwords new file mode 100644 index 00000000000..75fa2fc32b8 --- /dev/null +++ b/selftest/knownfail.d/unacceptable-passwords @@ -0,0 +1 @@ +^samba.tests.samba_tool.user_check_password_script.samba.tests.samba_tool.user_check_password_script.UserCheckPwdTestCase.test_checkpassword_unacceptable\(chgdcpass:local\) \ No newline at end of file diff --git a/selftest/target/Samba4.pm b/selftest/target/Samba4.pm index 02cdfc18bad..195e9b88044 100755 --- a/selftest/target/Samba4.pm +++ b/selftest/target/Samba4.pm @@ -1993,7 +1993,7 @@ sub provision_chgdcpass($$) print "PROVISIONING CHGDCPASS...\n"; # This environment disallows the use of this password # (and also removes the default AD complexity checks) - my $unacceptable_password = "widk3Dsle32jxdBdskldsk55klASKQ"; + my $unacceptable_password = "Paßßword-widk3Dsle32jxdBdskldsk55klASKQ"; my $extra_smb_conf = " check password script = $self->{srcdir}/selftest/checkpassword_arg1.sh ${unacceptable_password} allow dcerpc auth level connect:lsarpc = yes -- 2.17.1 From b3a71bf847e3797582a2c657720726694fe424ba Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Baumbach?= Date: Tue, 6 Aug 2019 16:32:32 +0200 Subject: [PATCH 4/6] CVE-2019-14833 dsdb: send full password to check password script MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit utf8_len represents the number of characters (not bytes) of the password. If the password includes multi-byte characters it is required to write the total number of bytes to the check password script. Otherwise the last bytes of the password string would be ignored. Therefore we rename utf8_len to be clear what it does and does not represent. BUG: https://bugzilla.samba.org/show_bug.cgi?id=12438 Signed-off-by: Björn Baumbach Signed-off-by: Andrew Bartlett --- selftest/knownfail.d/unacceptable-passwords | 1 - source4/dsdb/common/util.c | 30 ++++++++++++++++----- 2 files changed, 24 insertions(+), 7 deletions(-) delete mode 100644 selftest/knownfail.d/unacceptable-passwords diff --git a/selftest/knownfail.d/unacceptable-passwords b/selftest/knownfail.d/unacceptable-passwords deleted file mode 100644 index 75fa2fc32b8..00000000000 --- a/selftest/knownfail.d/unacceptable-passwords +++ /dev/null @@ -1 +0,0 @@ -^samba.tests.samba_tool.user_check_password_script.samba.tests.samba_tool.user_check_password_script.UserCheckPwdTestCase.test_checkpassword_unacceptable\(chgdcpass:local\) \ No newline at end of file diff --git a/source4/dsdb/common/util.c b/source4/dsdb/common/util.c index e521ed09999..3ebec827404 100644 --- a/source4/dsdb/common/util.c +++ b/source4/dsdb/common/util.c @@ -2036,21 +2036,36 @@ enum samr_ValidationStatus samdb_check_password(TALLOC_CTX *mem_ctx, const uint32_t pwdProperties, const uint32_t minPwdLength) { - const char *utf8_pw = (const char *)utf8_blob->data; - size_t utf8_len = strlen_m(utf8_pw); char *password_script = NULL; + const char *utf8_pw = (const char *)utf8_blob->data; + + /* + * This looks strange because it is. + * + * The check for the number of characters in the password + * should clearly not be against the byte length, or else a + * single UTF8 character would count for more than one. + * + * We have chosen to use the number of 16-bit units that the + * password encodes to as the measure of length. This is not + * the same as the number of codepoints, if a password + * contains a character beyond the Basic Multilingual Plane + * (above 65535) it will count for more than one "character". + */ + + size_t password_characters_roughly = strlen_m(utf8_pw); /* checks if the "minPwdLength" property is satisfied */ - if (minPwdLength > utf8_len) { + if (minPwdLength > password_characters_roughly) { return SAMR_VALIDATION_STATUS_PWD_TOO_SHORT; } - /* checks the password complexity */ + /* We might not be asked to check the password complexity */ if (!(pwdProperties & DOMAIN_PASSWORD_COMPLEX)) { return SAMR_VALIDATION_STATUS_SUCCESS; } - if (utf8_len == 0) { + if (password_characters_roughly == 0) { return SAMR_VALIDATION_STATUS_NOT_COMPLEX_ENOUGH; } @@ -2058,6 +2073,7 @@ enum samr_ValidationStatus samdb_check_password(TALLOC_CTX *mem_ctx, if (password_script != NULL && *password_script != '\0') { int check_ret = 0; int error = 0; + ssize_t nwritten = 0; struct tevent_context *event_ctx = NULL; struct tevent_req *req = NULL; int cps_stdin = -1; @@ -2120,7 +2136,9 @@ enum samr_ValidationStatus samdb_check_password(TALLOC_CTX *mem_ctx, cps_stdin = samba_runcmd_export_stdin(req); - if (write(cps_stdin, utf8_pw, utf8_len) != utf8_len) { + nwritten = write(cps_stdin, utf8_blob->data, + utf8_blob->length); + if (nwritten != utf8_blob->length) { close(cps_stdin); cps_stdin = -1; TALLOC_FREE(password_script); -- 2.17.1 From 4087d16945f97479b46a2d5fbfc883f813959fd9 Mon Sep 17 00:00:00 2001 From: Andrew Bartlett Date: Tue, 15 Oct 2019 16:28:46 +1300 Subject: [PATCH 5/6] CVE-2019-14847 dsdb: Demonstrate the correct interaction of ranged_results style attributes and dirsync Incremental results are provided by a flag on the dirsync control, not by changing the attribute name. BUG: https://bugzilla.samba.org/show_bug.cgi?id=14040 Signed-off-by: Andrew Bartlett --- selftest/knownfail.d/dirsync | 1 + source4/dsdb/tests/python/dirsync.py | 26 ++++++++++++++++++++++++++ 2 files changed, 27 insertions(+) create mode 100644 selftest/knownfail.d/dirsync diff --git a/selftest/knownfail.d/dirsync b/selftest/knownfail.d/dirsync new file mode 100644 index 00000000000..bc49fe0d9bb --- /dev/null +++ b/selftest/knownfail.d/dirsync @@ -0,0 +1 @@ +^samba4.ldap.dirsync.python\(ad_dc_ntvfs\).__main__.ExtendedDirsyncTests.test_dirsync_linkedattributes_range\( \ No newline at end of file diff --git a/source4/dsdb/tests/python/dirsync.py b/source4/dsdb/tests/python/dirsync.py index 8b46357c670..78117bc364b 100755 --- a/source4/dsdb/tests/python/dirsync.py +++ b/source4/dsdb/tests/python/dirsync.py @@ -28,6 +28,7 @@ from samba.tests.subunitrun import TestProgram, SubunitOptions import samba.getopt as options import base64 +import ldb from ldb import LdbError, SCOPE_BASE from ldb import Message, MessageElement, Dn from ldb import FLAG_MOD_ADD, FLAG_MOD_DELETE @@ -588,6 +589,31 @@ class SimpleDirsyncTests(DirsyncBaseTests): class ExtendedDirsyncTests(SimpleDirsyncTests): + def test_dirsync_linkedattributes_range(self): + self.ldb_simple = self.get_ldb_connection(self.simple_user, self.user_pass) + res = self.ldb_admin.search(self.base_dn, + attrs=["member;range=1-1"], + expression="(name=Administrators)", + controls=["dirsync:1:0:0"]) + + self.assertTrue(len(res) > 0) + self.assertTrue(res[0].get("member;range=1-1") is None) + self.assertTrue(res[0].get("member") is not None) + self.assertTrue(len(res[0].get("member")) > 0) + + def test_dirsync_linkedattributes_range_user(self): + self.ldb_simple = self.get_ldb_connection(self.simple_user, self.user_pass) + try: + res = self.ldb_simple.search(self.base_dn, + attrs=["member;range=1-1"], + expression="(name=Administrators)", + controls=["dirsync:1:0:0"]) + except LdbError as e: + (num, _) = e.args + self.assertEquals(num, ldb.ERR_INSUFFICIENT_ACCESS_RIGHTS) + else: + self.fail() + def test_dirsync_linkedattributes(self): flag_incr_linked = 2147483648 self.ldb_simple = self.get_ldb_connection(self.simple_user, self.user_pass) -- 2.17.1 From e33b8c5651032b82ffa3631b37ddb93f2bfe3b8d Mon Sep 17 00:00:00 2001 From: Andrew Bartlett Date: Tue, 15 Oct 2019 15:44:34 +1300 Subject: [PATCH 6/6] CVE-2019-14847 dsdb: Correct behaviour of ranged_results when combined with dirsync BUG: https://bugzilla.samba.org/show_bug.cgi?id=14040 Signed-off-by: Andrew Bartlett --- selftest/knownfail.d/dirsync | 1 - source4/dsdb/samdb/ldb_modules/dirsync.c | 11 ++++---- .../dsdb/samdb/ldb_modules/ranged_results.c | 25 ++++++++++++++++--- 3 files changed, 28 insertions(+), 9 deletions(-) delete mode 100644 selftest/knownfail.d/dirsync diff --git a/selftest/knownfail.d/dirsync b/selftest/knownfail.d/dirsync deleted file mode 100644 index bc49fe0d9bb..00000000000 --- a/selftest/knownfail.d/dirsync +++ /dev/null @@ -1 +0,0 @@ -^samba4.ldap.dirsync.python\(ad_dc_ntvfs\).__main__.ExtendedDirsyncTests.test_dirsync_linkedattributes_range\( \ No newline at end of file diff --git a/source4/dsdb/samdb/ldb_modules/dirsync.c b/source4/dsdb/samdb/ldb_modules/dirsync.c index 00f24bd6d59..96cec7774cf 100644 --- a/source4/dsdb/samdb/ldb_modules/dirsync.c +++ b/source4/dsdb/samdb/ldb_modules/dirsync.c @@ -1014,7 +1014,7 @@ static int dirsync_ldb_search(struct ldb_module *module, struct ldb_request *req } /* - * check if there's an extended dn control + * check if there's a dirsync control */ control = ldb_request_get_control(req, LDB_CONTROL_DIRSYNC_OID); if (control == NULL) { @@ -1343,11 +1343,12 @@ static int dirsync_ldb_search(struct ldb_module *module, struct ldb_request *req } /* - * Remove our control from the list of controls + * Mark dirsync control as uncritical (done) + * + * We need this so ranged_results knows how to behave with + * dirsync */ - if (!ldb_save_controls(control, req, NULL)) { - return ldb_operr(ldb); - } + control->critical = false; dsc->schema = dsdb_get_schema(ldb, dsc); /* * At the begining we make the hypothesis that we will return a complete diff --git a/source4/dsdb/samdb/ldb_modules/ranged_results.c b/source4/dsdb/samdb/ldb_modules/ranged_results.c index 13bf3a2d0a9..98438799997 100644 --- a/source4/dsdb/samdb/ldb_modules/ranged_results.c +++ b/source4/dsdb/samdb/ldb_modules/ranged_results.c @@ -35,14 +35,14 @@ struct rr_context { struct ldb_module *module; struct ldb_request *req; + bool dirsync_in_use; }; static struct rr_context *rr_init_context(struct ldb_module *module, struct ldb_request *req) { - struct rr_context *ac; - - ac = talloc_zero(req, struct rr_context); + struct ldb_control *dirsync_control = NULL; + struct rr_context *ac = talloc_zero(req, struct rr_context); if (ac == NULL) { ldb_set_errstring(ldb_module_get_ctx(module), "Out of Memory"); return NULL; @@ -51,6 +51,16 @@ static struct rr_context *rr_init_context(struct ldb_module *module, ac->module = module; ac->req = req; + /* + * check if there's a dirsync control (as there is an + * interaction between these modules) + */ + dirsync_control = ldb_request_get_control(req, + LDB_CONTROL_DIRSYNC_OID); + if (dirsync_control != NULL) { + ac->dirsync_in_use = true; + } + return ac; } @@ -82,6 +92,15 @@ static int rr_search_callback(struct ldb_request *req, struct ldb_reply *ares) ares->response, ares->error); } + if (ac->dirsync_in_use) { + /* + * We return full attribute values when mixed with + * dirsync + */ + return ldb_module_send_entry(ac->req, + ares->message, + ares->controls); + } /* LDB_REPLY_ENTRY */ temp_ctx = talloc_new(ac->req); -- 2.17.1