From 9a3ee861e43f84d48ef47998ceeb3bbf29f0c948 Mon Sep 17 00:00:00 2001 From: Jeremy Allison 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 Reviewed-by: Andrew Bartlett --- 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 @@ -639,46 +639,6 @@ WERROR _winreg_AbortSystemShutdown(struct pipes_struct *p, return (ret == 0) ? WERR_OK : WERR_ACCESS_DENIED; } -/******************************************************************* - ********************************************************************/ - -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; snumin.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; } /******************************************************************* -- 2.17.1