Commit 4c1b4d9e authored by Mathieu Parent's avatar Mathieu Parent

Add patch for CVE-2019-3880 Save registry file outside share as unprivileged user in Samba 4.x

parent ecdb31ca
From a803d2524b8c06e2c360db0c686a212ac49f7321 Mon Sep 17 00:00:00 2001
From: Jeremy Allison <jra@samba.org>
Date: Thu, 21 Mar 2019 14:51:30 -0700
Subject: [PATCH] CVE-2019-3880 s3: rpc: winreg: Remove implementations of
SaveKey/RestoreKey.
The were not using VFS backend calls and could only work
locally, and were unsafe against symlink races and other
security issues.
If the incoming handle is valid, return WERR_BAD_PATHNAME.
[MS-RRP] states "The format of the file name is implementation-specific"
so ensure we don't allow this.
As reported by Michael Hanselmann.
BUG: https://bugzilla.samba.org/show_bug.cgi?id=13851
Signed-off-by: Jeremy Allison <jra@samba.org>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
---
source3/rpc_server/winreg/srv_winreg_nt.c | 92 ++-----------------------------
1 file changed, 4 insertions(+), 88 deletions(-)
diff --git a/source3/rpc_server/winreg/srv_winreg_nt.c b/source3/rpc_server/winreg/srv_winreg_nt.c
index d9ee8d0602d..816c6bb2a12 100644
--- a/source3/rpc_server/winreg/srv_winreg_nt.c
+++ b/source3/rpc_server/winreg/srv_winreg_nt.c
@@ -640,46 +640,6 @@ WERROR _winreg_AbortSystemShutdown(struct pipes_struct *p,
}
/*******************************************************************
- ********************************************************************/
-
-static int validate_reg_filename(TALLOC_CTX *ctx, char **pp_fname )
-{
- char *p = NULL;
- int num_services = lp_numservices();
- int snum = -1;
- const char *share_path = NULL;
- char *fname = *pp_fname;
-
- /* convert to a unix path, stripping the C:\ along the way */
-
- if (!(p = valid_share_pathname(ctx, fname))) {
- return -1;
- }
-
- /* has to exist within a valid file share */
-
- for (snum=0; snum<num_services; snum++) {
- if (!lp_snum_ok(snum) || lp_printable(snum)) {
- continue;
- }
-
- share_path = lp_path(talloc_tos(), snum);
-
- /* make sure we have a path (e.g. [homes] ) */
- if (strlen(share_path) == 0) {
- continue;
- }
-
- if (strncmp(share_path, p, strlen(share_path)) == 0) {
- break;
- }
- }
-
- *pp_fname = p;
- return (snum < num_services) ? snum : -1;
-}
-
-/*******************************************************************
_winreg_RestoreKey
********************************************************************/
@@ -687,36 +647,11 @@ WERROR _winreg_RestoreKey(struct pipes_struct *p,
struct winreg_RestoreKey *r)
{
struct registry_key *regkey = find_regkey_by_hnd( p, r->in.handle );
- char *fname = NULL;
- int snum = -1;
- if ( !regkey )
+ if ( !regkey ) {
return WERR_INVALID_HANDLE;
-
- if ( !r->in.filename || !r->in.filename->name )
- return WERR_INVALID_PARAMETER;
-
- fname = talloc_strdup(p->mem_ctx, r->in.filename->name);
- if (!fname) {
- return WERR_NOT_ENOUGH_MEMORY;
}
-
- DEBUG(8,("_winreg_RestoreKey: verifying restore of key [%s] from "
- "\"%s\"\n", regkey->key->name, fname));
-
- if ((snum = validate_reg_filename(p->mem_ctx, &fname)) == -1)
- return WERR_BAD_PATHNAME;
-
- /* user must posses SeRestorePrivilege for this this proceed */
-
- if ( !security_token_has_privilege(p->session_info->security_token, SEC_PRIV_RESTORE)) {
- return WERR_ACCESS_DENIED;
- }
-
- DEBUG(2,("_winreg_RestoreKey: Restoring [%s] from %s in share %s\n",
- regkey->key->name, fname, lp_servicename(talloc_tos(), snum) ));
-
- return reg_restorekey(regkey, fname);
+ return WERR_BAD_PATHNAME;
}
/*******************************************************************
@@ -727,30 +662,11 @@ WERROR _winreg_SaveKey(struct pipes_struct *p,
struct winreg_SaveKey *r)
{
struct registry_key *regkey = find_regkey_by_hnd( p, r->in.handle );
- char *fname = NULL;
- int snum = -1;
- if ( !regkey )
+ if ( !regkey ) {
return WERR_INVALID_HANDLE;
-
- if ( !r->in.filename || !r->in.filename->name )
- return WERR_INVALID_PARAMETER;
-
- fname = talloc_strdup(p->mem_ctx, r->in.filename->name);
- if (!fname) {
- return WERR_NOT_ENOUGH_MEMORY;
}
-
- DEBUG(8,("_winreg_SaveKey: verifying backup of key [%s] to \"%s\"\n",
- regkey->key->name, fname));
-
- if ((snum = validate_reg_filename(p->mem_ctx, &fname)) == -1 )
- return WERR_BAD_PATHNAME;
-
- DEBUG(2,("_winreg_SaveKey: Saving [%s] to %s in share %s\n",
- regkey->key->name, fname, lp_servicename(talloc_tos(), snum) ));
-
- return reg_savekey(regkey, fname);
+ return WERR_BAD_PATHNAME;
}
/*******************************************************************
--
2.11.0
......@@ -8,3 +8,4 @@ add-so-version-to-private-libraries
heimdal-rfc3454.txt
nsswitch-Add-try_authtok-option-to-pam_winbind.patch
smbd.service-Run-update-apparmor-samba-profile-befor.patch
CVE-2019-3880-v4-9-02.patch
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