CVE-2000-0524: Medium severity Microsoft Outlook vulnerability
Microsoft Outlook and Outlook Express allow remote attackers to cause a denial of service by sending email messages with blank fields such as BCC, Reply-To, Return-Path, or From.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Compensating control
At the email perimeter (MTA/gateway) or using Microsoft Exchange transport/edge rules, reject, drop, or quarantine incoming messages that contain blank/empty header fields for BCC, Reply-To, Return-Path, or From. Implement header validation to block messages missing required sender/envelope fields to prevent the described denial-of-service vector.
- Operational
Monitor mail server and gateway logs for incoming messages with blank BCC, Reply-To, Return-Path, or From fields; alert on spikes and temporarily block or throttle offending source IPs or senders until the issue is mitigated.
Event History
Frequently Asked Questions
What is the severity of CVE-2000-0524?
CVE-2000-0524 is classified as a denial of service vulnerability, allowing remote attackers to disrupt email functionality.
How do I fix CVE-2000-0524?
To mitigate CVE-2000-0524, upgrading to the latest version of Microsoft Outlook or Exchange Server is recommended.
Which versions of software are affected by CVE-2000-0524?
CVE-2000-0524 affects Microsoft Outlook 97 and Microsoft Exchange Server 4.0 and 5.0.
What causes the vulnerability in CVE-2000-0524?
CVE-2000-0524 is caused by handling email messages with blank fields such as BCC, Reply-To, Return-Path, or From.
Who should be concerned about CVE-2000-0524?
Organizations using the affected versions of Microsoft Outlook or Exchange Server should be concerned about CVE-2000-0524 due to its potential for denial of service.