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Fencer Vulns
medium 5.9

CVE-2021-41171 json

Bypass bruteforce protection on login form in elabftw

published 2021-10-22 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-28276

cvss
5.9
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.9%
EPSS 1.9% chance of exploitation in 30 days, percentile 80%
public exploits
0
none known

Summary

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.

Patch / fix

  • elabftw elabftw 4.1.0

Exploit prediction

1.94% chance of exploitation in the next 30 days, higher than 80% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • exploit-db.com https://www.exploit-db.com/docs/50436 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
NVD 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 4.0 AV:N/AC:L/Au:S/C:P/I:N/A:N

Affected products

  • elabftw elabftw

Classification

Weakness
  • CWE-307 Improper Restriction of Excessive Authentication Attempts

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.