From: "Fabian Grünbichler" <f.gruenbichler@proxmox.com>
To: pve-devel@lists.proxmox.com
Subject: [pve-devel] [PATCH access-control 2/2] acls: restrict less-privileged ACL modifications
Date: Mon, 5 Jun 2023 16:21:37 +0200 [thread overview]
Message-ID: <20230605142137.854891-2-f.gruenbichler@proxmox.com> (raw)
In-Reply-To: <20230605142137.854891-1-f.gruenbichler@proxmox.com>
there are currently three possibilities to modify ACLs without the
'Permissions.Modify' privilege in PVE::RPCEnvironment::check_perm_modify:
if ($path =~ m|^/storage/.+$|) {
push @$testperms, 'Datastore.Allocate';
} elsif ($path =~ m|^/vms/.+$|) {
push @$testperms, 'VM.Allocate';
} elsif ($path =~ m|^/pool/.+$|) {
push @$testperms, 'Pool.Allocate';
}
lock those down by only allowing the currently authenticated user to hand out a
subset of their own privileges, never more.
for example, this still allows a PVEVMAdmin to create ACLs for other
users/tokens with PVEVMUser (on '/vm/XXX'), but not with Administrator or
PVEPermAdmin.
Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
---
Notes:
this one is also a breaking change, but a bit more niche -> IMHO a callout in the release notes is sufficient.
src/PVE/API2/ACL.pm | 24 +++++++++++++++++++++++-
1 file changed, 23 insertions(+), 1 deletion(-)
diff --git a/src/PVE/API2/ACL.pm b/src/PVE/API2/ACL.pm
index f0c9efb..93adb78 100644
--- a/src/PVE/API2/ACL.pm
+++ b/src/PVE/API2/ACL.pm
@@ -148,9 +148,12 @@ __PACKAGE__->register_method ({
PVE::AccessControl::lock_user_config(
sub {
-
my $cfg = cfs_read_file("user.cfg");
+ my $rpcenv = PVE::RPCEnvironment::get();
+ my $authuser = $rpcenv->get_user();
+ my $auth_user_privs = $rpcenv->permissions($authuser, $path);
+
my $propagate = 1;
if (defined($param->{propagate})) {
@@ -163,6 +166,25 @@ __PACKAGE__->register_method ({
die "role '$role' does not exist\n"
if !$cfg->{roles}->{$role};
+ if (!$auth_user_privs->{'Permissions.Modify'}) {
+ # 'perm-modify' allows /vms/* with VM.Allocate and similar restricted use cases
+ # filter those to only allow handing out a subset of currently active privs
+ my $role_privs = $cfg->{roles}->{$role};
+ my $verb = $param->{delete} ? 'remove' : 'add';
+ foreach my $priv (keys $role_privs->%*) {
+ raise_param_exc({ role => "Cannot $verb role '$role' - requires 'Permissions.Modify' or superset of privileges." })
+ if !defined($auth_user_privs->{$priv});
+
+ # propagation is only potentially problematic for adding ACLs, not removing..
+ raise_param_exc({ role => "Cannot $verb role '$role' with propagation - requires 'Permissions.Modify' or propagated superset of privileges." })
+ if $propagate && $auth_user_privs->{$priv} != $propagate && !$param->{delete};
+ }
+
+ # NoAccess has no privs, needs an explicit check
+ raise_param_exc({ role => "Cannot $verb role '$role' - requires 'Permissions.Modify'"})
+ if $role eq 'NoAccess';
+ }
+
foreach my $group (split_list($param->{groups})) {
die "group '$group' does not exist\n"
--
2.39.2
next prev parent reply other threads:[~2023-06-05 14:21 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-05 14:21 [pve-devel] [PATCH access-control 1/2] roles: restrict Permissions.Modify to Administrator Fabian Grünbichler
2023-06-05 14:21 ` Fabian Grünbichler [this message]
2023-06-07 9:18 ` [pve-devel] applied-series: " Thomas Lamprecht
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