Improper Restriction of Excessive Authentication Attempts in Firefly III

Published: 2021-07-26 | Updated: 2021-09-20
Risk Medium
Patch available YES
Number of vulnerabilities 1
CVE-ID CVE-2021-3663
Exploitation vector Network
Public exploit N/A
Vulnerable software
Firefly III
Client/Desktop applications / Other client software

Vendor James Cole

Security Bulletin

This security bulletin contains one medium risk vulnerability.

1) Improper Restriction of Excessive Authentication Attempts

EUVDB-ID: #VU55292

Risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-3663

CWE-ID: CWE-307 - Improper Restriction of Excessive Authentication Attempts

Exploit availability: No


The vulnerability allows a remote attacker to compromise the target system.

The vulnerability exists due to the affected software does not implement sufficient measures to prevent multiple failed authentication attempts within in a short time frame. A remote attacker can perform a brute-force attack and gain access to sensitive information on the system.


Install updates from vendor's website.

Vulnerable software versions

Firefly III: 5.5.0 - 5.5.12

CPE2.3 External links

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.