GHSA-fxq4-r6mr-9x64
CSRF Vuln can expose user's QRcode
GHSA-fxq4-r6mr-9x64 is a vulnerability with no CVSS score yet in flask-security-too, published April 8, 2021. No source lists public exploit code. Fixed in flask-security-too 3.4.5.
- Severity
- UnratedNo CVSS score yet
- Exploit chance
- UnscoredNo EPSS score yet
- Exploitation
- None knownNot on CISA’s or ENISA’s lists
- Fixed in
3.4.5flask-security-too +1 more
Description
Impact
When a user is setting up two-factor authentication using an authenticator app, a QRcode is generated and made available via a GET request to /tf-qrcode. Since GETs do not have any CSRF protection, it is possible a malicious 3rd party could access the QRcode and therefore gain access to two-factor authentication codes. Note that the /tf-qrcode endpoint is ONLY accessible while the user is initially setting up their device. Once setup is complete, there is no vulnerability.
Patches
This is fixed in the upcoming 4.0.0 release.
Workarounds
You can provide your own URL for fetching the QRcode by defining SECURITY_TWO_FACTOR_QRCODE_URL and providing your own implementation (that presumably required a POST with CSRF protection). This would require changing the two-factor setup template as well.
References
None.
For more information
If you have any questions or comments about this advisory:
- Read this pull request: #423
Affected packages
| Package | Affected | Fixed |
|---|---|---|
flask-security-tooPyPI | 3.2.0 up to 3.4.5 | 3.4.5 |
flask-security-tooPyPI | 3.2.0 up to 3.4.5, plus listed versions 3.3.03.3.0rc13.3.0rc23.3.0rc33.3.1 Show 7 moreShow less3.3.23.3.33.4.03.4.13.4.23.4.33.4.4 | 3.4.5 |
What each source reports
GitHub AdvisoriesNo score
CSRF Vuln can expose user's QRcode
Impact
When a user is setting up two-factor authentication using an authenticator app, a QRcode is generated and made available via a GET request to /tf-qrcode. Since GETs do not have any CSRF protection, it is possible a malicious 3rd party could access the QRcode and therefore gain access to two-factor authentication codes. Note that the /tf-qrcode endpoint is ONLY accessible while the user is initially setting up their device. Once setup is complete, there is no vulnerability.
Patches
This is fixed in the upcoming 4.0.0 release.
Workarounds
You can provide your own URL for fetching the QRcode by defining SECURITY_TWO_FACTOR_QRCODE_URL and providing your own implementation (that presumably required a POST with CSRF protection). This would require changing the two-factor setup template as well.
References
None.
For more information
If you have any questions or comments about this advisory:
- Read this pull request: #423
- Record
GHSA-fxq4-r6mr-9x64- Weakness
- CWE-352
- Updated
- 2026-11-02
OSVNo score
CSRF Vuln can expose user's QRcode
Impact
When a user is setting up two-factor authentication using an authenticator app, a QRcode is generated and made available via a GET request to /tf-qrcode. Since GETs do not have any CSRF protection, it is possible a malicious 3rd party could access the QRcode and therefore gain access to two-factor authentication codes. Note that the /tf-qrcode endpoint is ONLY accessible while the user is initially setting up their device. Once setup is complete, there is no vulnerability.
Patches
This is fixed in the upcoming 4.0.0 release.
Workarounds
You can provide your own URL for fetching the QRcode by defining SECURITY_TWO_FACTOR_QRCODE_URL and providing your own implementation (that presumably required a POST with CSRF protection). This would require changing the two-factor setup template as well.
References
None.
For more information
If you have any questions or comments about this advisory:
- Read this pull request: #423
- Record
GHSA-fxq4-r6mr-9x64- Weakness
- CWE-352
- Updated
- 2026-11-02
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | GitHub Advisories, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.