CVE intelligence and bounded remediation

CVE-2019-1126 — Microsoft Windows Server 2012 security vulnerability

Medium CVSS 5.3

A security feature bypass vulnerability exists in Active Directory Federation Services (ADFS) which could allow an attacker to bypass the extranet lockout policy.To exploit this vulnerability, an attacker could run a specially crafted application, which would allow an attacker to launch a password brute-force attack or cause account lockouts in Active Directory.This security update corrects how ADFS handles external authentication requests., aka 'ADFS Security Feature Bypass Vulnerability'. This CVE ID is unique from CVE-2019-0975.

Severity
Medium
CVSS
5.3 (3.0)
Published
2019-07-15
CISA KEV
Not currently listed
Ecosystem
windows/system
Weaknesses
CWE-307

Affected products

  • microsoft / windows_server_2012 / r2
  • microsoft / windows_server_2016
  • microsoft / windows_server_2016 / 1803
  • microsoft / windows_server_2016 / 1903
  • microsoft / windows_server_2019

Matched remediation archetype

Authentication bypass and missing authentication

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Map every affected endpoint and protocol path, including alternate ports, legacy routes, recovery flows, service accounts, and machine-to-machine access.
  • Confirm which deployments enable the affected authentication mode and whether the interface is reachable from untrusted networks.
  • Review session, token, credential, and proxy trust configuration without attempting account takeover.

Remediate safely

  • Apply the supported fix and centralize fail-closed authentication before protected request handling.
  • Remove default or embedded credentials, rotate affected secrets and sessions, and bind authentication decisions to the intended audience and channel.
  • Add negative tests for alternate routes, malformed or absent credentials, recovery flows, and proxy-derived identity.

Authoritative sources

Complete CVE record and remediation plan

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