Firefly III has a MFA bypass in oauth flow
Impact
A MFA bypass in the Firefly III OAuth flow may allow malicious users to bypass the MFA-check. This allows malicious users to use password spraying to gain access to your Firefly III data using passwords stolen from other sources. As OAuth applications are easily enumerable using an incrementing id, an attacker could try sign an OAuth application up to a users profile quite easily if they have created one. The attacker would also need to know the victims username and password.
Patches
Problem has been patched in Firefly III v6.1.17 and up.
Workarounds
- Use a unique password for your Firefly III instance,
- Store your password securely, i.e. in a password manager or in your head.
References
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Composer package | grumpydictator/firefly-iii | < 6.1.17 | 6.1.17 |
References
- https://github.com/firefly-iii/firefly-iii/security/advisories/GHSA-4gm4-c4mh-4p7w
- https://nvd.nist.gov/vuln/detail/CVE-2024-37893
- https://github.com/firefly-iii/firefly-iii
- https://owasp.org/www-community/attacks/Password_Spraying_Attack
- https://www.menlosecurity.com/what-is/highly-evasive-adaptive-threats-heat/mfa-bypass
- CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N- Weakness (CWE)
CWE-287, CWE-288- Platform
- Composer
- Package
grumpydictator/firefly-iii- Disclosed
- 17.06.2024
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-4gm4-c4mh-4p7w - CC BY 4.0
Vulnerability history: grumpydictator/firefly-iii
All published vulnerabilities of this package (Composer package), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 26
- First → latest
- 08.2021 06.2026
- Without a fix
- 3
- Exploited in attacks
- 0
Severity breakdown
- Critical 1
- High 1
- Medium 22
- Low 2
Disclosures per year
- 2021: 12
- 2022: 5
- 2023: 3
- 2024: 3
- 2025: 0
- 2026: 3
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Firefly III has a MFA bypass in oauth flow this entry
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