CVE-2021-37843

CRITICAL

Atlassian SAML Single Sign-On < 2.5.9, < 3.5.6, < 3.6.6.1 - Unauthenticated Authentication Bypass

Title source: llm

Description

The resolution SAML SSO apps for Atlassian products allow a remote attacker to login to a user account when only the username is known (i.e., no other authentication is provided). The fixed versions are for Jira: 3.6.6.1, 4.0.12, 5.0.5; for Confluence 3.6.6, 4.0.12, 5.0.5; for Bitbucket 2.5.9, 3.6.6, 4.0.12, 5.0.5; for Bamboo 2.5.9, 3.6.6, 4.0.12, 5.0.5; and for Fisheye 2.5.9.

References (1)

Core 1

Core References

Third Party Advisory x_refsource_misc

https://wiki.resolution.de/doc/saml-sso/5.0.x/all/security-advisories/2021-07-29-authentication-bypass-network-attacker-can-login-to-users-accounts-when-usernames-are-known

Scores

CVSS v3 9.8

EPSS 0.0091

EPSS Percentile 76.0%

Attack Vector NETWORK

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Details

CWE

CWE-306

Status published

Products (3)

atlassian/saml_single_sign_on < 2.5.9 (3 CPE variants)

atlassian/saml_single_sign_on < 3.5.6

atlassian/saml_single_sign_on < 3.6.6.1

Published Aug 02, 2021

Tracked Since Feb 18, 2026