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Live TOTP secret included in user data export ZIP

Moderate
thorsten published GHSA-xhgx-2wj8-g4pj Aug 20, 2026

Package

composer phpmyfaq/phpmyfaq (Composer)

Affected versions

<= 4.1.7

Patched versions

4.1.8

Description

Authorized research notice: This vulnerability was discovered during authorized security research in an isolated lab environment against a local instance of phpMyFAQ (main @ 9435f34, 4.2.0-alpha.2; issues cross-checked against the 4.1 stable branch where applicable). No production systems or third-party data were accessed. I am reporting under coordinated disclosure and will not publish details for 90 days from this report to allow a fix. Please confirm receipt within 7 days.

Summary

The GDPR-style self-service export (POST /api/user/data/export) produces a ZIP whose userdata.json contains the account's live TOTP shared secret in plaintext. The export is a user-facing download that typically transits browsers, download folders, mailboxes and cloud backups — all of which then silently hold a working 2FA seed. Anyone obtaining the archive can generate valid one-time codes and defeat the account's second factor. Credential material must never appear in a data export; the password hash is correctly excluded, but the TOTP seed is not.

Credit: Ahmed Ibrahim (@skeletonsec)

Affected versions

  • Verified on main @ 9435f34 (4.2.0-alpha.2 nightly, phpmyfaq/src/phpMyFAQ/Controller/Frontend/Api/UserController.php:176)
  • Same defect verified on the 4.1 stable branch (phpmyfaq/src/phpMyFAQ/Controller/Frontend/UserController.php:161), affecting the latest stable release line.

Root cause

exportUserData() builds the export array including 'secret' => (string) $this->currentUser->getUserData('secret') — the raw TOTP seed from faquserdata — with no redaction or field allowlist.

Proof of concept

  1. Enable 2FA for a test account.
  2. Log in (full 2FA), GET /user/ucp, take the export-userdata CSRF token.
  3. curl -X POST https://target/api/user/data/export -b cookies -d 'pmf-csrf-token=T&userid=2' -o export.zip → 200 application/zip.
  4. unzip -p export.zip userdata.json → contains "secret": "<LIVE-TOTP-SEED>" and "twofactor_enabled": 1. Codes derived from the exported seed were verified against the app's own TOTP library.

Impact

Persistent 2FA compromise for any user who has ever exported their data with 2FA enabled; the seed stays valid until 2FA is reset, long after the export is forgotten in a downloads folder or backup.

Suggested remediation

Remove secret from the export array and maintain an explicit allowlist of non-credential export fields (audit faquserdata columns such as secret and webauthnkeys against it).

CWE

CWE-200: Exposure of Sensitive Information

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 v4 base metrics

Exploitability Metrics
Attack Vector Network
Attack Complexity Low
Attack Requirements None
Privileges Required Low
User interaction None
Vulnerable System Impact Metrics
Confidentiality Low
Integrity None
Availability None
Subsequent System Impact Metrics
Confidentiality None
Integrity None
Availability None

CVSS v4 base metrics

Exploitability Metrics
Attack Vector: This metric reflects the context by which vulnerability exploitation is possible. This metric value (and consequently the resulting severity) will be larger the more remote (logically, and physically) an attacker can be in order to exploit the vulnerable system. The assumption is that the number of potential attackers for a vulnerability that could be exploited from across a network is larger than the number of potential attackers that could exploit a vulnerability requiring physical access to a device, and therefore warrants a greater severity.
Attack Complexity: This metric captures measurable actions that must be taken by the attacker to actively evade or circumvent existing built-in security-enhancing conditions in order to obtain a working exploit. These are conditions whose primary purpose is to increase security and/or increase exploit engineering complexity. A vulnerability exploitable without a target-specific variable has a lower complexity than a vulnerability that would require non-trivial customization. This metric is meant to capture security mechanisms utilized by the vulnerable system.
Attack Requirements: This metric captures the prerequisite deployment and execution conditions or variables of the vulnerable system that enable the attack. These differ from security-enhancing techniques/technologies (ref Attack Complexity) as the primary purpose of these conditions is not to explicitly mitigate attacks, but rather, emerge naturally as a consequence of the deployment and execution of the vulnerable system.
Privileges Required: This metric describes the level of privileges an attacker must possess prior to successfully exploiting the vulnerability. The method by which the attacker obtains privileged credentials prior to the attack (e.g., free trial accounts), is outside the scope of this metric. Generally, self-service provisioned accounts do not constitute a privilege requirement if the attacker can grant themselves privileges as part of the attack.
User interaction: This metric captures the requirement for a human user, other than the attacker, to participate in the successful compromise of the vulnerable system. This metric determines whether the vulnerability can be exploited solely at the will of the attacker, or whether a separate user (or user-initiated process) must participate in some manner.
Vulnerable System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the VULNERABLE SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the VULNERABLE SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the VULNERABLE SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
Subsequent System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the SUBSEQUENT SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the SUBSEQUENT SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the SUBSEQUENT SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

CVE ID

No known CVE

Weaknesses

Exposure of Sensitive Information to an Unauthorized Actor

The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. Learn more on MITRE.

Credits