diff --git a/src/core/dbus-manager.c b/src/core/dbus-manager.c
index 78cab48f85..5a7f70d78b 100644
--- a/src/core/dbus-manager.c
+++ b/src/core/dbus-manager.c
@@ -1265,10 +1265,6 @@ static int list_units_filtered(sd_bus_message *message, void *userdata, sd_bus_e
 
         /* Anyone can call this method */
 
-        r = mac_selinux_access_check(message, "status", reterr_error);
-        if (r < 0)
-                return r;
-
         r = sd_bus_message_new_method_return(message, &reply);
         if (r < 0)
                 return r;
@@ -1281,6 +1277,10 @@ static int list_units_filtered(sd_bus_message *message, void *userdata, sd_bus_e
                 if (k != u->id)
                         continue;
 
+                r = mac_selinux_unit_access_check(u, message, "status", /* reterr_error= */ NULL);
+                if (r < 0)
+                        continue; /* silently skip units the caller is not allowed to see */
+
                 if (!unit_passes_filter(u, states, patterns))
                         continue;
 
diff --git a/src/core/varlink-manager.c b/src/core/varlink-manager.c
index 997bdc08d0..6ae837376a 100644
--- a/src/core/varlink-manager.c
+++ b/src/core/varlink-manager.c
@@ -207,6 +207,10 @@ int vl_method_describe_manager(sd_varlink *link, sd_json_variant *parameters, sd
         if (r != 0)
                 return r;
 
+        r = mac_selinux_access_check_varlink(link, "status");
+        if (r < 0)
+                return r;
+
         r = sd_json_buildo(
                         &v,
                         SD_JSON_BUILD_PAIR_CALLBACK("context", manager_context_build_json, manager),
diff --git a/src/core/varlink-unit.c b/src/core/varlink-unit.c
index 2404c553d7..e8b86845a2 100644
--- a/src/core/varlink-unit.c
+++ b/src/core/varlink-unit.c
@@ -523,6 +523,10 @@ int vl_method_list_units(sd_varlink *link, sd_json_variant *parameters, sd_varli
                 if (k != unit->id)
                         continue;
 
+                r = mac_selinux_unit_access_check_varlink(unit, link, "status");
+                if (r < 0)
+                        continue; /* silently skip units the caller is not allowed to see */
+
                 r = list_unit_one(link, unit);
                 if (r < 0)
                         return r;
diff --git a/src/journal-remote/journal-upload.c b/src/journal-remote/journal-upload.c
index c4eab80a1f..e6cb5dabc2 100644
--- a/src/journal-remote/journal-upload.c
+++ b/src/journal-remote/journal-upload.c
@@ -307,10 +307,13 @@ int start_upload(Uploader *u,
                                     LOG_ERR, return -EXFULL);
                 }
 
-                if (STRPTR_IN_SET(arg_trust, "-", "all"))
+                if (STRPTR_IN_SET(arg_trust, "-", "all")) {
+                        log_info("Server certificate verification disabled.");
                         easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0L,
                                     LOG_ERR, return -EUCLEAN);
-                else if (arg_trust || startswith(u->url, "https://"))
+                        easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0L,
+                                    LOG_ERR, return -EUCLEAN);
+                } else if (arg_trust || startswith(u->url, "https://"))
                         easy_setopt(curl, CURLOPT_CAINFO, arg_trust ?: TRUST_FILE,
                                     LOG_ERR, return -EXFULL);
 
diff --git a/src/login/logind-dbus.c b/src/login/logind-dbus.c
index bef9f51aef..9668bf0609 100644
--- a/src/login/logind-dbus.c
+++ b/src/login/logind-dbus.c
@@ -59,6 +59,7 @@
 #include "signal-util.h"
 #include "sleep-config.h"
 #include "stdio-util.h"
+#include "string-util.h"
 #include "strv.h"
 #include "terminal-util.h"
 #include "tmpfile-util.h"
@@ -3582,6 +3583,46 @@ static int property_get_boot_loader_entries(
         return sd_bus_message_close_container(reply);
 }
 
+static int wall_message_validate(const char *wall_message, sd_bus_error *error) {
+        if (strlen(wall_message) > WALL_MESSAGE_MAX)
+                return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS,
+                                         "Wall message too long, maximum permitted length is %u characters.",
+                                         WALL_MESSAGE_MAX);
+
+        if (string_has_cc(wall_message, /* ok= */ "\n\t"))
+                return sd_bus_error_set(error,
+                                        SD_BUS_ERROR_INVALID_ARGS,
+                                        "Wall message contains control characters, refusing.");
+
+        return 0;
+}
+
+static int property_set_wall_message(
+                sd_bus *bus,
+                const char *path,
+                const char *interface,
+                const char *property,
+                sd_bus_message *value,
+                void *userdata,
+                sd_bus_error *error) {
+
+        char **p = ASSERT_PTR(userdata);
+        const char *s;
+        int r;
+
+        assert(value);
+
+        r = sd_bus_message_read(value, "s", &s);
+        if (r < 0)
+                return r;
+
+        r = wall_message_validate(s, error);
+        if (r < 0)
+                return r;
+
+        return free_and_strdup_warn(p, empty_to_null(s));
+}
+
 static int method_set_wall_message(
                 sd_bus_message *message,
                 void *userdata,
@@ -3598,10 +3639,9 @@ static int method_set_wall_message(
         if (r < 0)
                 return r;
 
-        if (strlen(wall_message) > WALL_MESSAGE_MAX)
-                return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS,
-                        "Wall message too long, maximum permitted length is %u characters.",
-                        WALL_MESSAGE_MAX);
+        r = wall_message_validate(wall_message, error);
+        if (r < 0)
+                return r;
 
         /* Short-circuit the operation if the desired state is already in place, to
          * avoid an unnecessary polkit permission check. */
@@ -3764,7 +3804,7 @@ static const sd_bus_vtable manager_vtable[] = {
         SD_BUS_VTABLE_START(0),
 
         SD_BUS_WRITABLE_PROPERTY("EnableWallMessages", "b", bus_property_get_bool, bus_property_set_bool, offsetof(Manager, wall_messages), 0),
-        SD_BUS_WRITABLE_PROPERTY("WallMessage", "s", NULL, NULL, offsetof(Manager, wall_message), 0),
+        SD_BUS_WRITABLE_PROPERTY("WallMessage", "s", NULL, property_set_wall_message, offsetof(Manager, wall_message), 0),
 
         SD_BUS_PROPERTY("NAutoVTs", "u", NULL, offsetof(Manager, n_autovts), SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_PROPERTY("KillOnlyUsers", "as", NULL, offsetof(Manager, kill_only_users), SD_BUS_VTABLE_PROPERTY_CONST),
diff --git a/src/machine/machine-dbus.c b/src/machine/machine-dbus.c
index 2dab827d41..c096a012d8 100644
--- a/src/machine/machine-dbus.c
+++ b/src/machine/machine-dbus.c
@@ -26,6 +26,7 @@
 #include "signal-util.h"
 #include "string-util.h"
 #include "strv.h"
+#include "user-util.h"
 
 static BUS_DEFINE_PROPERTY_GET_ENUM(property_get_class, machine_class, MachineClass);
 static BUS_DEFINE_PROPERTY_GET2(property_get_state, "s", Machine, machine_get_state, machine_state_to_string);
@@ -366,6 +367,9 @@ int bus_machine_method_open_shell(sd_bus_message *message, void *userdata, sd_bu
                 return r;
         user = isempty(user) ? "root" : user;
 
+        if (!valid_user_group_name(user, VALID_USER_RELAX))
+                return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid user name '%s'", user);
+
         /* Ensure only root can shell into the root namespace. This is to avoid unprivileged users registering
          * a process they own in the root user namespace, and then shelling in as root or another user. Note that
          * the shell operation is privileged and requires 'auth_admin', so we do not need to check the caller's uid,
diff --git a/src/machine/machine.c b/src/machine/machine.c
index da26bdf7a0..535128692e 100644
--- a/src/machine/machine.c
+++ b/src/machine/machine.c
@@ -1103,11 +1103,10 @@ int machine_start_shell(
 
 char** machine_default_shell_args(const char *user) {
         _cleanup_strv_free_ char **args = NULL;
-        int r;
 
         assert(user);
 
-        args = new0(char*, 3 + 1);
+        args = new0(char*, 5 + 1);
         if (!args)
                 return NULL;
 
@@ -1119,14 +1118,19 @@ char** machine_default_shell_args(const char *user) {
         if (!args[1])
                 return NULL;
 
-        r = asprintf(&args[2],
-                     "shell=$(getent passwd %s 2>/dev/null | { IFS=: read _ _ _ _ _ _ x; echo \"$x\"; })\n"\
-                     "exec \"${shell:-/bin/sh}\" -l", /* -l is means --login */
-                     user);
-        if (r < 0) {
-                args[2] = NULL;
+        args[2] = strdup(
+                     "shell=$(getent passwd \"$1\" 2>/dev/null | { IFS=: read _ _ _ _ _ _ x; echo \"$x\"; })\n"
+                     "exec \"${shell:-/bin/sh}\" -l"); /* -l means --login */
+        if (!args[2])
+                return NULL;
+
+        args[3] = strdup("sh"); /* $0 placeholder for sh -c */
+        if (!args[3])
+                return NULL;
+
+        args[4] = strdup(user); /* becomes $1 in the script */
+        if (!args[4])
                 return NULL;
-        }
 
         return TAKE_PTR(args);
 }