CVE-2025-5719

Executive Summary

CVE-2025-5719 is an authentication bypass vulnerability affecting a wallet application, allowing unauthenticated attackers to access specific privileged pages without valid credentials. The vulnerability's root cause lies in flawed session validation or access control logic that fails to enforce authentication on certain routes. The affected product and exact version range are currently unidentified, and while a patch is claimed by a single source, this has not been independently confirmed. Successful exploitation could lead to unauthorized access to sensitive financial data, transaction manipulation, and account takeover, posing a direct financial and reputational risk to affected organizations.

Technical Analysis

CVE-2025-5719 describes an authentication bypass flaw in a wallet application. Based on the vulnerability class (CWE-287 — Improper Authentication), the underlying mechanism is typically one of the following:

1. Missing Authorization Checks: The application fails to enforce authentication middleware on specific routes or endpoints. In many web frameworks (e.g., Express.js, Django, Spring), developers may annotate certain handlers as "public" or omit an @login_required decorator, inadvertently exposing administrative or user-specific functionality. An attacker can directly request these URLs (e.g., /api/v1/transactions, /admin/dashboard) without a session token, and the server responds with sensitive data.

2. Broken Session Validation: The application validates user identity via a client-supplied parameter (e.g., user_id, account_id in URL or POST body) instead of the server-side session token. An attacker can simply modify this parameter to impersonate another user or escalate privileges. This is a classic "assumed immutable data" flaw where the server trusts user-controlled input for authorization decisions.

3. Logic Flaw in Redirect/Authentication Flow: The authentication check may be bypassed by manipulating the Referer header, X-Forwarded-For, or by accessing the page via a different HTTP method (GET vs POST). For instance, the login check might only be enforced on POST requests, leaving GET endpoints unprotected.

Attack Surface: The wallet application likely exposes multiple web interfaces — a user-facing portal, an API gateway, and potentially an admin backend. The specific pages accessible without authentication are unknown but likely include financial functions: balance queries, transaction history, transfer endpoints, or admin reporting dashboards. The attack surface is network-exposed web interfaces (HTTP/HTTPS), making it remotely exploitable.

Code-Level Perspective: In a typical vulnerable implementation, the route definition might look like:

# Vulnerable Flask example
@app.route('/wallet/balance')
def get_balance():
    # Missing @login_required decorator
    user_id = request.args.get('user_id')
    return query_balance(user_id)

An attacker requests /wallet/balance?user_id=12345 without any session cookie, and the server returns the balance for account 12345. The lack of server-side session verification is the core defect.

Exploitation Scenarios

Despite the absence of a public PoC, the following concrete attack chain is realistic for this vulnerability class:

Step 1 — Reconnaissance / Target Identification: The attacker scans for the wallet application using Shodan dorks like http.title:"wallet" or http.html:"login" http.html:"balance". They identify the application's technology stack via HTTP headers (e.g., Server: nginx, X-Powered-By: Express) and fingerprint the framework using tools like Wappalyzer. They enumerate common endpoints by crawling the application and inspecting the JavaScript bundle for API route paths.

Step 2 — Trigger / Weaponization: The attacker crafts direct HTTP requests to sensitive endpoints, removing any authentication cookies or tokens. They use tools like Burp Suite, cURL, or custom Python scripts to send requests like:

GET /wallet/balance?user_id=1001 HTTP/1.1
Host: target-wallet.com
Cookie: (absent)

GET /api/v1/transactions/list HTTP/1.1
Host: target-wallet.com

They also fuzz for parameter names (userId, accountID, uid) and try HTTP verb tampering (POST instead of GET, or OPTIONS to bypass WAF rules). If the application uses JWT tokens, they attempt to alter the alg header to none or change the sub claim in a forged token.

Step 3 — Payload / Execution: If the first endpoint is blocked, the attacker brute-forces directory paths using a wordlist (e.g., SecLists/Discovery/Web-Content/common-api-endpoints.txt). They manually test each discovered route without authentication to confirm which return data with HTTP 200 instead of 401/403. For exposed API endpoints, they send crafted JSON payloads to trigger unauthorized actions:

POST /api/v1/transfer HTTP/1.1
Content-Type: application/json

{"from_account": "1001", "to_account": "attacker_controlled", "amount": 5000}

Step 4 — Post-Exploitation Impact: Once inside, the attacker enumerates all user accounts by iterating user_id parameters, harvesting personally identifiable information (PII), financial records, and transaction history. They may initiate unauthorized fund transfers, modify wallet balances, or reset user passwords via exposed admin endpoints. In a backend admin panel bypass, they could escalate to full system compromise by uploading a web shell or altering database records directly through an unprotected CRUD API.

(Note: This is a network-accessible web application vulnerability; physical access is not required, and exploitation is fully remote.)

Impact Assessment

Business Impact: This authentication bypass exposes the core financial logic of the wallet application, which may result in:

• Financial Loss: Direct theft of funds through unauthorized transfers or balance manipulation.
• Data Breach: Exposure of PII (names, addresses, phone numbers), financial records, and transaction histories of all users.
• Reputational Damage: Loss of customer trust, regulatory fines (GDPR, PCI DSS), and mandatory breach notifications.
• Regulatory Non-Compliance: Potential violation of financial services regulations (e.g., PSD2, SOC 2, PCI DSS).

Affected Systems: The wallet application itself, any integrated backend databases, and downstream services that rely on the wallet's API (e.g., payment gateways, accounting systems). If the wallet is a mobile app, the backend REST API is equally exposed.

Blast Radius: Given no CVSS score is available, we infer from the attack surface (network-exposed, unauthenticated access to financial pages) that this is likely High severity (7.0-8.9) by standard metrics, assuming confidentiality and integrity loss but limited availability impact. The actual blast radius depends on which pages are exposed: if only read-only balance queries are affected, the impact is data leak; if transfer/withdraw functions are exposed, the impact is catastrophic.

Detection Guidance

Sigma Rule

title: Unauthenticated Access to Wallet Application Pages
id: a5f8c2d1-6f4e-4b8a-9e2d-3c1f9a8b7e6d
status: experimental
description: Detects HTTP requests to wallet application sensitive endpoints without authentication cookies or tokens.
logsource:
  category: webserver
  detection:
    selection:
      cs-uri-extension: 
        - "/wallet/balance"
        - "/api/v1/transactions"
        - "/admin/dashboard"
        - "/api/v1/transfer"
      sc-status: 200
      cs-cookie: 
        - null
        - ""
    condition: selection
  level: high
  tags:
    - attack.t1190
    - cve.2025.5719

YARA Rule

rule CVE_2025_5719_Wallet_AuthBypass {
    meta:
        author = "ValterSecurity Research"
        date = "2025-01-15"
        description = "Detects suspicious requests targeting wallet endpoints without auth"
        cve = "CVE-2025-5719"
        severity = "high"
    strings:
        $s1 = "/wallet/balance" ascii nocase
        $s2 = "/api/v1/transfer" ascii nocase
        $s3 = "/admin/dashboard" ascii nocase
        $s4 = "user_id=" ascii nocase
        $s5 = "account_id=" ascii nocase
        $s6 = "Cookie:" ascii
    condition:
        (any of ($s1, $s2, $s3) and any of ($s4, $s5)) and not $s6
}

Suricata IDS Rule

alert http any any -> any any (msg:"CVE-2025-5719 Wallet Auth Bypass Attempt"; flow:to_server,established; http.uri; content:"/wallet/balance"; http.uri; content:"user_id="; http.cookie; content:!"Cookie:"; classtype:attempted-admin; sid:20255719; rev:1;)

Elastic Detection

sequence by host.name
  [ network where event.type == "connection" and destination.port == 443 ]
  [ http where http.request.method == "GET" and
    (url.path == "/wallet/balance" or url.path == "/api/v1/transactions") and
    not http.request.headers.cookie != null ]
  [ http where http.response.status_code == 200 ]

Splunk SPL Query

index=web sourcetype=access_combined
| where (uri_path="/wallet/balance" OR uri_path="/api/v1/transactions" OR uri_path="/admin/dashboard")
  AND status=200
  AND (NOT cookie="*" OR cookie="")
| stats count by src_ip, uri_path, user_agent
| where count > 3

Wazuh OSSEC Rule

<group name="cve_2025_5719,">
  <rule id="757104" level="12">
    <decoded_as>json</decoded_as>
    <field name="url">\./wallet/balance|\./api/v1/transactions|\./admin/dashboard</field>
    <field name="status">^200$</field>
    <field name="cookie">^$</field>
    <description>CVE-2025-5719: Unauthenticated wallet endpoint access detected</description>
    <group>authentication_failure,</group>
  </rule>
</group>

Mitigation & Patch Guidance

Patch Confidence: 2/4 — a single source claims a patch exists, but it has not been independently confirmed nor has an exact version been identified. Validate any vendor advisory before assuming a fix is complete.

1. Immediate Mitigations:

   • Restrict Network Access: Immediately place the wallet application behind a VPN, IP allowlist, or Web Application Firewall (WAF) with rules blocking unauthenticated access to sensitive routes.
   • Manual Testing: Manually audit all routes with no authentication middleware. Use tools like curl or Burp Suite to identify and explicitly block any endpoint that returns data without a valid session.
   • Session Validation: Implement server-side session validation middleware that rejects any request missing a valid session token, regardless of route.
   • Disable Unused Features: If admin or transfer endpoints are not business-critical, disable them entirely until the patch is verified.

2. Patch/Upgrade Steps:

   • Monitor the vendor's official security advisory page for CVE-2025-5719.
   • When a patched version is released, apply it in a staging environment first; test that authentication is enforced on all previously exposed pages.
   • Verify the patch by re-running the detection rules above and confirming no unauthenticated access returns HTTP 200.
   • Rebuild any containers/AMIs with the patched version and redeploy via your orchestration pipeline (e.g., helm upgrade, docker compose pull).

3. Long-Term Hardening:

   • Code Review: Incorporate automated SAST tools (e.g., Semgrep, Checkmarx) with rules for missing authentication decorators.
   • Default-Deny Framework: Configure the application framework (e.g., Spring Security, Django's @login_required) to deny all routes by default, requiring explicit opt-in for anonymous access.
   • Rate Limiting & Anomaly Detection: Deploy API rate limiting to slow brute-force enumeration post-exploit.
   • Monitoring: Alert on any 200 response to sensitive wallet endpoints missing authentication headers, using the Sigma/Splunk rules above.

References

1. NVD Entry: https://nvd.nist.gov/vuln/detail/CVE-2025-5719
2. MITRE ATT&CK Technique T1190: https://attack.mitre.org/techniques/T1190/
3. CWE-287 (Improper Authentication): https://cwe.mitre.org/data/definitions/287.html
4. OWASP Authentication Bypass Cheat Sheet: https://cheatsheetseries.owasp.org/cheatsheets/Authentication_Cheat_Sheet.html
5. CISA KEV Catalog: https://www.cisa.gov/known-exploited-vulnerabilities-catalog (CVE-2025-5719 is NOT listed; no exploit-in-the-wild evidence has been reported)

Note: No threat actor campaigns or exploit-in-the-wild evidence have been publicly documented for this CVE as of the writing date. The exact vendor and affected product remain unidentified; monitor NVD updates for CNA assignment.