From fc6022b9b19473076c4236fdf4ac474f44ca73e2 Mon Sep 17 00:00:00 2001 From: Jeremy Allison Date: Mon, 5 Aug 2019 13:39:53 -0700 Subject: [PATCH 1/7] 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 2bd61b1d2c2..e708e911b97 100644 --- a/source3/libsmb/proto.h +++ b/source3/libsmb/proto.h @@ -722,6 +722,9 @@ 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 167f78aa97af6502cb2027dc9dad40399b0a9c4f Mon Sep 17 00:00:00 2001 From: Jeremy Allison Date: Tue, 6 Aug 2019 12:08:09 -0700 Subject: [PATCH 2/7] 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 1cfa50ffbac..3cdf68dc24b 100644 --- a/source3/libsmb/cli_smb2_fnum.c +++ b/source3/libsmb/cli_smb2_fnum.c @@ -1017,6 +1017,13 @@ 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 e6de467a763b93152eef27726957a32879268fb7 Mon Sep 17 00:00:00 2001 From: Andrew Bartlett Date: Thu, 19 Sep 2019 11:50:01 +1200 Subject: [PATCH 3/7] 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 b565d466477..d7c22ce4e23 100755 --- a/selftest/target/Samba4.pm +++ b/selftest/target/Samba4.pm @@ -1986,7 +1986,7 @@ sub provision_chgdcpass($$) my $extra_provision_options = undef; # This environment disallows the use of this password # (and also removes the default AD complexity checks) - my $unacceptable_password = "widk3Dsle32jxdBdskldsk55klASKQ"; + my $unacceptable_password = "Paßßword-widk3Dsle32jxdBdskldsk55klASKQ"; push (@{$extra_provision_options}, "--dns-backend=BIND9_DLZ"); my $ret = $self->provision($prefix, "domain controller", -- 2.17.1 From 70078d4ddf3b842eeadee058dadeef82ec4edf0b 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 4/7] 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 | 33 +++++++++++++++++---- 2 files changed, 27 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 18f700370a3..c7893bff43b 100644 --- a/source4/dsdb/common/util.c +++ b/source4/dsdb/common/util.c @@ -2088,21 +2088,36 @@ 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; } @@ -2110,6 +2125,7 @@ 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; struct samba_runcmd_state *run_cmd = NULL; @@ -2134,7 +2150,12 @@ enum samr_ValidationStatus samdb_check_password(TALLOC_CTX *mem_ctx, tevent_timeval_current_ofs(10, 0), 100, 100, cmd, NULL); run_cmd = tevent_req_data(req, struct samba_runcmd_state); - if (write(run_cmd->fd_stdin, utf8_pw, utf8_len) != utf8_len) { + nwritten = write(run_cmd->fd_stdin, + utf8_blob->data, + utf8_blob->length); + if (nwritten != utf8_blob->length) { + close(run_cmd->fd_stdin); + run_cmd->fd_stdin = -1; TALLOC_FREE(password_script); TALLOC_FREE(event_ctx); return SAMR_VALIDATION_STATUS_PASSWORD_FILTER_ERROR; -- 2.17.1 From ea39bdd6293041af668f1bfdfea39a725733bad3 Mon Sep 17 00:00:00 2001 From: Douglas Bagnall Date: Fri, 3 May 2019 17:27:51 +1200 Subject: [PATCH 5/7] CVE-2019-14847 dsdb/modules/dirsync: ensure attrs exist (CID 1107212) BUG: https://bugzilla.samba.org/show_bug.cgi?id=14040 Signed-off-by: Douglas Bagnall Reviewed-by: Gary Lockyer (cherry picked from commit 23f72c4d712f8d1fec3d67a66d477709d5b0abe2) --- source4/dsdb/samdb/ldb_modules/dirsync.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/source4/dsdb/samdb/ldb_modules/dirsync.c b/source4/dsdb/samdb/ldb_modules/dirsync.c index b5510eccd24..62a66fef8d4 100644 --- a/source4/dsdb/samdb/ldb_modules/dirsync.c +++ b/source4/dsdb/samdb/ldb_modules/dirsync.c @@ -343,6 +343,10 @@ skip: attr = dsdb_attribute_by_lDAPDisplayName(dsc->schema, el->name); + if (attr == NULL) { + continue; + } + keep = false; if (attr->linkID & 1) { -- 2.17.1 From bdb3e3f669bd991da819040e726e003e4e2b841d Mon Sep 17 00:00:00 2001 From: Andrew Bartlett Date: Tue, 15 Oct 2019 16:28:46 +1300 Subject: [PATCH 6/7] 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 136f4d3bba6..b6f7022a50b 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 @@ -590,6 +591,31 @@ 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 77b10b360f4ffb7ac90bc5fce0a80306515c1aca Mon Sep 17 00:00:00 2001 From: Andrew Bartlett Date: Tue, 15 Oct 2019 15:44:34 +1300 Subject: [PATCH 7/7] 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 62a66fef8d4..4ac5faad403 100644 --- a/source4/dsdb/samdb/ldb_modules/dirsync.c +++ b/source4/dsdb/samdb/ldb_modules/dirsync.c @@ -998,7 +998,7 @@ 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) { @@ -1327,11 +1327,12 @@ 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