Don't allow a configure file which is writeable by the Exim user or group

(Bug 1044, CVE-2010-4345)

5 files changed, 8 insertions, 7 deletions

diff --git a/src/src/EDITME b/src/src/EDITME
index 050d9ad10..285e5b656 100644
--- a/src/src/EDITME
+++ b/src/src/EDITME
@@ -430,14 +430,13 @@ FIXED_NEVER_USERS=root
 
 
 #------------------------------------------------------------------------------
-# By default, Exim insists that its configuration file be owned either by root
-# or by the Exim user. You can specify one additional permitted owner here.
+# By default, Exim insists that its configuration file be owned by root. You
+# can specify one additional permitted owner here.
 
 # CONFIGURE_OWNER=
 
 # If the configuration file is group-writeable, Exim insists by default that it
-# is owned by root or the Exim user. You can specify one additional permitted
-# group owner here.
+# is owned by root. You can specify one additional permitted group owner here.
 
 # CONFIGURE_GROUP=
 
diff --git a/src/src/config.h.defaults b/src/src/config.h.defaults
index c6895b621..9f0eba0fe 100644
--- a/src/src/config.h.defaults
+++ b/src/src/config.h.defaults
@@ -161,5 +161,6 @@ just in case. */
 #define DNS_MAXNAME                1024
 #define EXPAND_MAXN                  20
 #define ROOT_UID                      0
+#define ROOT_GID                      0
 
 /* End of config.h.defaults */
diff --git a/src/src/globals.c b/src/src/globals.c
index 645cdb130..9b77d876b 100644
--- a/src/src/globals.c
+++ b/src/src/globals.c
@@ -946,6 +946,7 @@ int     rewrite_existflags     = 0;
 uschar *rfc1413_hosts          = US"*";
 int     rfc1413_query_timeout  = 5;
 /* BOOL    rfc821_domains         = FALSE;  <<< on the way out */
+uid_t   root_gid               = ROOT_GID;
 uid_t   root_uid               = ROOT_UID;
 
 router_instance  *routers  = NULL;
diff --git a/src/src/globals.h b/src/src/globals.h
index b036def7c..d66880e67 100644
--- a/src/src/globals.h
+++ b/src/src/globals.h
@@ -610,6 +610,7 @@ extern int     rewrite_existflags;     /* Indicate which headers have rewrites *
 extern uschar *rfc1413_hosts;          /* RFC hosts */
 extern int     rfc1413_query_timeout;  /* Timeout on RFC 1413 calls */
 /* extern BOOL    rfc821_domains;  */       /* If set, syntax is 821, not 822 => being abolished */
+extern uid_t   root_gid;               /* The gid for root */
 extern uid_t   root_uid;               /* The uid for root */
 extern router_info routers_available[];/* Vector of available routers */
 extern router_instance *routers;       /* Chain of instantiated routers */
diff --git a/src/src/readconf.c b/src/src/readconf.c
index 954d546a4..080305834 100644
--- a/src/src/readconf.c
+++ b/src/src/readconf.c
@@ -2883,13 +2883,12 @@ if (!config_changed)
     log_write(0, LOG_MAIN|LOG_PANIC_DIE, "failed to stat configuration file %s",
       big_buffer);
 
-  if ((statbuf.st_uid != root_uid &&             /* owner not root */
-       statbuf.st_uid != exim_uid                /* owner not exim */
+  if ((statbuf.st_uid != root_uid                /* owner not root */
        #ifdef CONFIGURE_OWNER
        && statbuf.st_uid != config_uid           /* owner not the special one */
        #endif
          ) ||                                    /* or */
-      (statbuf.st_gid != exim_gid                /* group not exim & */
+      (statbuf.st_gid != root_gid                /* group not root & */
        #ifdef CONFIGURE_GROUP
        && statbuf.st_gid != config_gid           /* group not the special one */
        #endif