CVE-2021-41171
CVSS v3
8.8
HIGH
EPSS Score
1.9 %
exploit probability, as of 2026-09-25
CISA KEV
No
known exploited
Exploitation
—
SSVC status
Description
eLabFTW is an open source electronic lab notebook manager for research teams. In versions of eLabFTW before 4.1.0, it allows attackers to bypass a brute-force protection mechanism by using many different forged PHPSESSID values in HTTP Cookie header. This issue has been addressed by implementing brute force login protection, as recommended by Owasp with Device Cookies. This mechanism will not impact users and will effectively thwart any brute-force attempts at guessing passwords. The only correct way to address this is to upgrade to version 4.1.0. Adding rate limitation upstream of the eLabFTW service is of course a valid option, with or without upgrading.
Technical details
- Published
- 2021-10-22
Frequently asked questions
What is CVE-2021-41171?
eLabFTW is an open source electronic lab notebook manager for research teams. In versions of eLabFTW before 4.1.0, it allows attackers to bypass a brute-force protection mechanism by using many different forged PHPSESSID values in HTTP Cookie header. This issue has been addressed by implementing brute force login protection, as recommended by Owasp with Device Cookies. This mechanism will not impact users and will effectively thwart any brute-force attempts at guessing passwords. The only correct way to address this is to upgrade to version 4.1.0. Adding rate limitation upstream of the eLabFTW service is of course a valid option, with or without upgrading.
Is CVE-2021-41171 actively exploited?
Active exploitation of CVE-2021-41171 has not been confirmed. Its EPSS score was 1.9% on 2026-09-25, the estimated probability of exploitation in the next 30 days.
What is the CVSS score for CVE-2021-41171?
CVE-2021-41171 has a CVSS v3 base score of 8.8 (HIGH severity).
Is CVE-2021-41171 affecting your environment?
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