An issue was discovered in Bitrix24 Bitrix Framework (1c site management) 20.0.

published 2020-12-02 5 y ago modified 2026-06-17 4 mo ago also EUVD-2020-20690

cvss: 6.5; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 1.1%; EPSS 1.1% chance of exploitation in 30 days, percentile 66%
public exploits: 0; none known

An issue was discovered in Bitrix24 Bitrix Framework (1c site management) 20.0. An "User enumeration and Improper Restriction of Excessive Authentication Attempts" vulnerability exists in the admin login form, allowing a remote user to enumerate users in the administrator group. This also allows brute-force attacks on the passwords of users not in the administrator group.

Exploit prediction

1.14% chance of exploitation in the next 30 days, higher than 66% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

justrealstag.medium.com https://justrealstag.medium.com/user-enumeration-improper-restriction-of-excessive-authentication-attempts-in-bitrix-98933a97e0e6 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
NVD	3.1	6.5	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
NVD	2.0	4.0	AV:N/AC:L/Au:S/C:P/I:N/A:N

Classification

Weakness

CWE-307 Improper Restriction of Excessive Authentication Attempts

References

justrealstag.medium.com /user-enumeration-improper-restriction-of-excessive-authentication-attempts-in-bitrix-98933a97e0e6
exploit, third-party-advisory

Sources

CVE List CVE-2020-28206
NVD CVE-2020-28206

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.

Summary