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phpMyFAQ: Attachment download allowed without dlattachment right (broken access control)

Moderate severity GitHub Reviewed Published Jan 23, 2026 in thorsten/phpMyFAQ • Updated Jan 28, 2026

Package

composer phpmyfaq/phpmyfaq (Composer)

Affected versions

<= 4.0.16

Patched versions

4.0.17
composer thorsten/phpmyfaq (Composer)
<= 4.0.16
4.0.17

Description

Summary

A logged‑in user without the dlattachment right can download FAQ attachments. This is due to a permissive permission check in attachment.php that treats the mere presence of a right key as authorization and a flawed group/user logic expression.

Details

In attachment.php, the access decision uses:
($groupPermission || ($groupPermission && $userPermission)) && isset($permission['dlattachment'])
isset() returns true even when the right value is false, and the logic simplifies to $groupPermission for some permission modes. As a result, a user without dlattachment can still access the attachment.

PoC

Precondition: A non‑admin user exists; an attachment is associated to a FAQ record; records.allowDownloadsForGuests = false.
Log in as a non‑admin user without dlattachment.
Request the attachment download endpoint.

curl -c /tmp/pmf_api_cookies.txt \
  -H 'Content-Type: application/json' \
  -d '{"username":"tester","password":"Test1234!"}' \
  http://192.168.40.16/phpmyfaq/api/v3.0/login

curl -i -b /tmp/pmf_api_cookies.txt \
  "http://192.168.40.16/phpmyfaq/index.php?action=attachment&id=1"

Impact

Unauthorized users can download attachments (confidentiality breach). Depending on content, this may expose sensitive documents.

References

@thorsten thorsten published to thorsten/phpMyFAQ Jan 23, 2026
Published to the GitHub Advisory Database Jan 23, 2026
Reviewed Jan 23, 2026
Published by the National Vulnerability Database Jan 24, 2026
Last updated Jan 28, 2026

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(2nd percentile)

Weaknesses

Improper Access Control

The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor. Learn more on MITRE.

CVE ID

CVE-2026-24420

GHSA ID

GHSA-7p9h-m7m8-vhhv

Source code

Credits

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