CVE-2024-43547 Overview
CVE-2024-43547 is an information disclosure vulnerability in the Windows Kerberos authentication protocol. Microsoft addressed the flaw in its October 2024 Patch Tuesday release. The issue affects a broad range of Windows client and server versions, including legacy Windows Server 2008 and current Windows 11 24H2 builds.
The vulnerability is categorized under [CWE-325: Missing Cryptographic Step], indicating that a required cryptographic operation was not performed. Successful exploitation exposes confidential data over the network, though attack complexity is high and no privileges or user interaction are required.
Critical Impact
An unauthenticated network attacker who successfully exploits this Kerberos flaw can access confidential authentication material, undermining the integrity of Windows identity protocols across domain-joined environments.
Affected Products
- Microsoft Windows 10 (versions 1507, 1607, 1809, 21H2, 22H2)
- Microsoft Windows 11 (versions 21H2, 22H2, 23H2, 24H2)
- Microsoft Windows Server 2008, 2012, 2012 R2, 2016, 2019, 2022, and 2022 23H2
Discovery Timeline
- 2024-10-08 - CVE-2024-43547 published to NVD by Microsoft
- 2024-10-08 - Microsoft releases security patch as part of October 2024 Patch Tuesday
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2024-43547
Vulnerability Analysis
CVE-2024-43547 is an information disclosure weakness in the Windows Kerberos implementation. Kerberos is the primary authentication protocol for Active Directory environments. It relies on symmetric-key cryptography and ticket exchanges to authenticate principals without transmitting passwords.
The flaw is mapped to [CWE-325: Missing Cryptographic Step]. This class of weakness occurs when an implementation omits a required cryptographic operation, such as encryption, integrity verification, or nonce validation. The result is that data expected to be protected may traverse the network in a state that permits recovery by an attacker.
Microsoft classifies the impact as a confidentiality-only issue. There is no integrity or availability impact according to the CVSS vector. The scope is unchanged, meaning only resources managed by the vulnerable Kerberos component are exposed.
Root Cause
Microsoft's public advisory does not enumerate the specific Kerberos exchange or code path affected. The [CWE-325] mapping indicates a missing cryptographic step in the Kerberos message flow. This omission allows sensitive protocol material to be observed or inferred by an attacker positioned to interact with the Kerberos service.
Attack Vector
Exploitation requires network access to a vulnerable Kerberos endpoint, typically a Windows domain controller or a Kerberos client. No authentication or user interaction is needed. The high attack complexity reflects conditions such as timing, positioning, or protocol-state prerequisites that an attacker must satisfy before information disclosure occurs.
Refer to the Microsoft CVE-2024-43547 Update Guide for the authoritative technical description.
Detection Methods for CVE-2024-43547
Indicators of Compromise
- Anomalous Kerberos traffic patterns on TCP/UDP port 88, including unusual pre-authentication requests or malformed AS-REQ and TGS-REQ messages.
- Unexpected Kerberos error events such as KRB_AP_ERR_MODIFIED or repeated ticket requests from a single source targeting multiple service principals.
- Windows Event Log entries 4768, 4769, and 4771 originating from unmanaged or previously unseen client addresses.
Detection Strategies
- Baseline normal Kerberos ticket request volume per host and alert on statistical deviations that suggest protocol probing.
- Correlate authentication logs from domain controllers with network telemetry to identify off-hours or non-domain sources initiating Kerberos exchanges.
- Monitor for patch compliance across all affected Windows versions using vulnerability management scans keyed to the October 2024 update baseline.
Monitoring Recommendations
- Forward Windows Security event channels from all domain controllers into a centralized logging pipeline for retention and correlation.
- Track Kerberos pre-authentication failures alongside ticket-granting service requests to detect reconnaissance attempts.
- Establish alerts for patch regression on affected systems following imaging or rollback operations.
How to Mitigate CVE-2024-43547
Immediate Actions Required
- Apply the October 2024 Microsoft security updates to all affected Windows client and server systems, prioritizing domain controllers.
- Inventory Windows Server 2008 and 2012 hosts, which require Extended Security Updates (ESU) to receive the patch.
- Validate patch deployment by confirming updated Kerberos-related binaries and reviewing update history on each system.
Patch Information
Microsoft released fixes for CVE-2024-43547 on October 8, 2024. Consult the Microsoft CVE-2024-43547 Update Guide for the KB article numbers corresponding to each affected Windows version. Deploy the update on all domain controllers first, then extend coverage to member servers and workstations.
Workarounds
- No official workaround has been published by Microsoft; patching is the required remediation path.
- Restrict inbound Kerberos traffic to authorized subnets using host and network firewall policies where operationally feasible.
- Segment domain controllers from untrusted networks and enforce administrative tiering to limit exposure of Kerberos endpoints.
# Verify installed updates on a Windows host
wmic qfe list brief /format:table
# PowerShell alternative to confirm October 2024 cumulative update is present
Get-HotFix | Sort-Object -Property InstalledOn -Descending | Select-Object -First 20
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
