From 1fe8857b4d90809ff5b160c73e3d2c28acd3ce65 Mon Sep 17 00:00:00 2001 From: Stefan Metzmacher Date: Wed, 30 Nov 2022 14:47:33 +0100 Subject: [PATCH] CVE-2022-38023 libcli/auth: add/use netlogon_creds_cli_warn_options() This warns the admin about insecure options BUG: https://bugzilla.samba.org/show_bug.cgi?id=15240 Signed-off-by: Stefan Metzmacher Reviewed-by: Andrew Bartlett Reviewed-by: Ralph Boehme (similar to commit 7e7adf86e59e8a673fbe87de46cef0d62221e800) [jsutton@samba.org Replaced call to tevent_cached_getpid() with one to getpid()] --- libcli/auth/netlogon_creds_cli.c | 66 ++++++++++++++++++++++++++++++++ libcli/auth/netlogon_creds_cli.h | 2 + 2 files changed, 68 insertions(+) diff --git a/libcli/auth/netlogon_creds_cli.c b/libcli/auth/netlogon_creds_cli.c index 030191174dc..3794d8b6b6e 100644 --- a/libcli/auth/netlogon_creds_cli.c +++ b/libcli/auth/netlogon_creds_cli.c @@ -205,6 +205,8 @@ static struct db_context *netlogon_creds_cli_global_db; NTSTATUS netlogon_creds_cli_set_global_db(struct loadparm_context *lp_ctx, struct db_context **db) { + netlogon_creds_cli_warn_options(lp_ctx); + if (netlogon_creds_cli_global_db != NULL) { return NT_STATUS_INVALID_PARAMETER_MIX; } @@ -219,6 +221,8 @@ NTSTATUS netlogon_creds_cli_open_global_db(struct loadparm_context *lp_ctx) struct db_context *global_db; int hash_size, tdb_flags; + netlogon_creds_cli_warn_options(lp_ctx); + if (netlogon_creds_cli_global_db != NULL) { return NT_STATUS_OK; } @@ -259,6 +263,68 @@ void netlogon_creds_cli_close_global_db(void) TALLOC_FREE(netlogon_creds_cli_global_db); } +void netlogon_creds_cli_warn_options(struct loadparm_context *lp_ctx) +{ + bool global_reject_md5_servers = lpcfg_reject_md5_servers(lp_ctx); + bool global_require_strong_key = lpcfg_require_strong_key(lp_ctx); + int global_client_schannel = lpcfg_client_schannel(lp_ctx); + bool global_seal_secure_channel = lpcfg_winbind_sealed_pipes(lp_ctx); + static bool warned_global_reject_md5_servers = false; + static bool warned_global_require_strong_key = false; + static bool warned_global_client_schannel = false; + static bool warned_global_seal_secure_channel = false; + static int warned_global_pid = 0; + int current_pid = getpid(); + + if (warned_global_pid != current_pid) { + warned_global_reject_md5_servers = false; + warned_global_require_strong_key = false; + warned_global_client_schannel = false; + warned_global_seal_secure_channel = false; + warned_global_pid = current_pid; + } + + if (!global_reject_md5_servers && !warned_global_reject_md5_servers) { + /* + * We want admins to notice their misconfiguration! + */ + DBG_ERR("CVE-2022-38023 (and others): " + "Please configure 'reject md5 servers = yes' (the default), " + "See https://bugzilla.samba.org/show_bug.cgi?id=15240\n"); + warned_global_reject_md5_servers = true; + } + + if (!global_require_strong_key && !warned_global_require_strong_key) { + /* + * We want admins to notice their misconfiguration! + */ + DBG_ERR("CVE-2022-38023 (and others): " + "Please configure 'require strong key = yes' (the default), " + "See https://bugzilla.samba.org/show_bug.cgi?id=15240\n"); + warned_global_require_strong_key = true; + } + + if (global_client_schannel != true && !warned_global_client_schannel) { + /* + * We want admins to notice their misconfiguration! + */ + DBG_ERR("CVE-2022-38023 (and others): " + "Please configure 'client schannel = yes' (the default), " + "See https://bugzilla.samba.org/show_bug.cgi?id=15240\n"); + warned_global_client_schannel = true; + } + + if (!global_seal_secure_channel && !warned_global_seal_secure_channel) { + /* + * We want admins to notice their misconfiguration! + */ + DBG_ERR("CVE-2022-38023 (and others): " + "Please configure 'winbind sealed pipes = yes' (the default), " + "See https://bugzilla.samba.org/show_bug.cgi?id=15240\n"); + warned_global_seal_secure_channel = true; + } +} + NTSTATUS netlogon_creds_cli_context_global(struct loadparm_context *lp_ctx, struct messaging_context *msg_ctx, const char *client_account, diff --git a/libcli/auth/netlogon_creds_cli.h b/libcli/auth/netlogon_creds_cli.h index d10197c2d2a..600242e1aea 100644 --- a/libcli/auth/netlogon_creds_cli.h +++ b/libcli/auth/netlogon_creds_cli.h @@ -35,6 +35,8 @@ NTSTATUS netlogon_creds_cli_set_global_db(struct loadparm_context *lp_ctx, struc NTSTATUS netlogon_creds_cli_open_global_db(struct loadparm_context *lp_ctx); void netlogon_creds_cli_close_global_db(void); +void netlogon_creds_cli_warn_options(struct loadparm_context *lp_ctx); + NTSTATUS netlogon_creds_cli_context_global(struct loadparm_context *lp_ctx, struct messaging_context *msg_ctx, const char *client_account,