CWE-290Weakness · CWE-290

CVE-2021-47923

CRITICAL · 9.8 CVSS v3.1 Published 2026-05-10
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Public exploit Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
OpenCart 3.0.3.8 contains a session fixation vulnerability that allows attackers to hijack user sessions by injecting arbitrary values into the OCSESSID cookie. Attackers can set malicious OCSESSID cookie values that the server accepts and maintains, enabling session takeover and unauthorized access to user accounts.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

OpenCart 3.0.3.8 fails to regenerate session IDs upon user authentication, allowing attackers to inject arbitrary values into the OCSESSID cookie. When a victim authenticates while using an attacker-controlled session ID, the attacker can then use that same ID to hijack the authenticated session and gain unauthorized access to user accounts.

MitigationImplement session ID regeneration (session_regenerate_id) after successful authentication and validate that session IDs are unpredictable. Additionally, configure the session cookie with secure, HttpOnly, and SameSite attributes to prevent client-side session theft.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify OpenCart version
    Check the version file in your OpenCart installation (commonly system/library/user or admin/index.php) or access the admin dashboard System > Information page to confirm the installed version.
    Affected if The installed version is 3.0.3.8 or falls within the 3.x branch where this session fixation flaw exists.
  2. Inspect OCSESSID cookie behavior
    Use browser developer tools or a command-line tool (curl) to send a request with an arbitrary OCSESSID cookie value (e.g., OCSESSID=attacker_controlled_id) and observe whether the server accepts and persists this value.
    Affected if The server accepts and returns the same arbitrary OCSESSID value without regenerating a new session ID.
  3. Verify session ID regeneration on login
    Set a known OCSESSID value, then authenticate with valid credentials while keeping the same cookie. After successful login, inspect the OCSESSID cookie again to see if a new session ID was generated.
    Affected if The session ID remains unchanged after successful authentication, allowing an attacker who pre-set the ID to hijack the authenticated session.
  4. Check session invalidation on logout
    Authenticate, then log out. Attempt to reuse the same OCSESSID cookie value to access protected endpoints or the admin area.
    Affected if The previous session remains valid after logout, enabling session reuse by an attacker.

A user is affected if their OpenCart version is 3.0.3.8 (or a vulnerable 3.x version) AND the server accepts arbitrary OCSESSID values without regenerating session IDs upon authentication.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Implement session ID regeneration (session_regenerate_id) after successful authentication and validate that session IDs are unpredictable. Additionally, configure the session cookie with secure, HttpOnly, and SameSite attributes to prevent client-side session theft.

Have this fixed Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing3.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,490
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,984.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2021-47923 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-47923 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data