PhpbbApplication

CVE-2020-5502

MEDIUM · 6.5 CVSS v3.1 Published 2020-01-15
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
72/100
Remediation priority · Elevated
Remotely reachable No privileges

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
phpBB 3.2.8 allows a CSRF attack that can approve pending group memberships.

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 · high confidence

phpBB 3.2.8 lacks proper CSRF tokens on the group membership approval function, allowing attackers to trick authenticated administrators into approving arbitrary pending group memberships via malicious links or embedded forms on third-party sites.

MitigationImplement anti-CSRF tokens (form tokens) on group membership approval actions and validate them server-side before processing membership approvals.

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

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
PhpbbApplication
Affected:= 3.2.8

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
Required
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
None

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

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 phpBB version
    Access the admin control panel (ACP) and navigate to the System tab, or check the docs/software version file in the phpBB installation directory
    Affected if Version is exactly 3.2.8
  2. Locate group membership approval code
    Navigate to the phpBB root directory and locate the file handling group membership operations, typically in includes/ or memberlist.php for the memberlist module
    Affected if The group membership approval function exists and is accessible in the installation
  3. Inspect group approval form for CSRF token
    Open the relevant PHP file that handles group membership approval and search for form token implementation or hidden token fields in the approval form
    Affected if No CSRF token (form token) is present in the group membership approval form code
  4. Check server-side token validation
    Review the PHP code that processes the group membership approval POST request to verify if token validation (such as check_form_key or similar) is performed before processing
    Affected if The approval processing code lacks server-side CSRF token validation

A user is affected if they run phpBB version 3.2.8 and the group membership approval form lacks CSRF token generation and server-side validation.

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 anti-CSRF tokens (form tokens) on group membership approval actions and validate them server-side before processing membership approvals.

Fix this in Phpbb Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,930
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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

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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-2020-5502 in production — separate from our analysis above.

No notes yet

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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