Publish GHSA-f346-8rp3-4h9h

Author: advisory-database[bot]

advisories/github-reviewed/2026/03/GHSA-f346-8rp3-4h9h/GHSA-f346-8rp3-4h9h.json

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+{
+  "schema_version": "1.4.0",
+  "id": "GHSA-f346-8rp3-4h9h",
+  "modified": "2026-03-27T15:42:20Z",
+  "published": "2026-03-27T15:42:20Z",
+  "aliases": [
+    "CVE-2026-33541"
+  ],
+  "summary": "TSPortal's Uncontrolled User Creation via Validation Side Effects Leads to Potential Denial of Service",
+  "details": "### Summary\nA flaw in TSPortal allowed attackers to create arbitrary user records in the database by abusing validation logic. While validation correctly rejected invalid usernames, a side effect within a validation rule caused user records to be created regardless of whether the request succeeded. This could be exploited to cause uncontrolled database growth, leading to a potential denial of service (DoS).\n\n### Details\nWhen submitting a Data Processing Agreement (DPA) request in TSPortal, the `DPAAlreadyLive` validation rule previously called `User::findOrCreate()`.\n\nThis method created a user record if one did not already exist.\n\nAlthough username validation (via `MirahezeUsernameRule`) correctly rejected invalid usernames, the `DPAAlreadyLive` rule was still executed during validation. Because it performed a state-changing operation, it created user records even when the overall validation failed and no DPA was created.\n\nAs a result:\n- Validation correctly rejected invalid input\n- However, user records were still inserted into the database as a side effect\n\nThese records were created:\n- Without a successful DPA request\n- Without audit logging tied to a completed action\n- Without visibility into their origin\n\n### Impact\nAn attacker could exploit this behavior by automating requests with invalid usernames, resulting in:\n\n- Mass creation of arbitrary user records\n- Unbounded database growth\n- Increased storage and indexing overhead\n- Potential degradation of application performance\n\nAt scale, this could lead to a denial of service condition due to resource exhaustion.\n\n### Proof of Concept\n1. Submit a DPA request using an invalid username\n2. Ensure the request fails validation due to `MirahezeUsernameRule`\n3. Observe that a corresponding user record is still created in the database\n\nThis behavior was confirmed prior to remediation.\n\n### Root Cause\nThe issue stemmed from:\n- Performing state-changing operations (`findOrCreate`) inside validation logic\n- Validation rules executing regardless of overall validation success\n- Lack of separation between validation and persistence layers\n\n### Mitigation\nThe issue has been fixed by removing database write operations from validation logic.\n\nSpecifically:\n- Replaced `User::findOrCreate()` with a non-mutating lookup (`User::firstWhere(...)`)\n- Ensured validation rules only perform read operations\n- Prevented user creation unless all validation passes",
+  "severity": [
+    {
+      "type": "CVSS_V3",
+      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"
+    }
+  ],
+  "affected": [
+    {
+      "package": {
+        "ecosystem": "Packagist",
+        "name": "miraheze/ts-portal"
+      },
+      "ranges": [
+        {
+          "type": "ECOSYSTEM",
+          "events": [
+            {
+              "introduced": "0"
+            },
+            {
+              "fixed": "34"
+            }
+          ]
+        }
+      ],
+      "database_specific": {
+        "last_known_affected_version_range": "<= 33"
+      }
+    }
+  ],
+  "references": [
+    {
+      "type": "WEB",
+      "url": "https://github.com/miraheze/TSPortal/security/advisories/GHSA-f346-8rp3-4h9h"
+    },
+    {
+      "type": "ADVISORY",
+      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-33541"
+    },
+    {
+      "type": "PACKAGE",
+      "url": "https://github.com/miraheze/TSPortal"
+    },
+    {
+      "type": "WEB",
+      "url": "https://issue-tracker.miraheze.org/T15115"
+    }
+  ],
+  "database_specific": {
+    "cwe_ids": [
+      "CWE-400",
+      "CWE-770"
+    ],
+    "severity": "MODERATE",
+    "github_reviewed": true,
+    "github_reviewed_at": "2026-03-27T15:42:20Z",
+    "nvd_published_at": "2026-03-26T21:17:05Z"
+  }
+}