CVE-1999-0284: Buffer Overflow
Denial of service to NT mail servers including Ipswitch, Mdaemon, and Exchange through a buffer overflow in the SMTP HELO command.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Configuration
Configure the mail servers to reject malformed HELO commands, enforce strict input validation on HELO, and restrict acceptance of SMTP from untrusted networks or relays until a vendor fix is available.
Mail servers (IBM Domino, Microsoft Exchange Server) HELO handling / SMTP acceptance from untrusted networks = reject malformed HELOs; restrict SMTP acceptance to trusted peers - Compensating control
Restrict inbound SMTP (TCP port 25) access to IBM Domino, Microsoft Exchange Server, Ipswitch and MDaemon hosts at the network perimeter to trusted IPs/networks only (block or allow-list source IPs).
- Compensating control
Deploy or enable IDS/IPS/WAF signatures to detect and block exploit attempts targeting the SMTP HELO command (malformed HELOs / buffer overflow attempts) against mail servers (IBM Domino, Microsoft Exchange Server, Ipswitch, MDaemon).
- Compensating control
Isolate affected mail servers from untrusted networks (place in a segregated VLAN or apply ACLs) until a vendor patch or workaround is available to prevent denial-of-service via SMTP HELO buffer overflow.
- Operational
Monitor mail server logs and network telemetry for crashes, excessive SMTP connections, or repeated malformed HELO commands and perform incident response (containment and forensic capture) if exploitation is observed.
Event History
Frequently Asked Questions
What is the severity of CVE-1999-0284?
CVE-1999-0284 is classified as a denial of service vulnerability affecting multiple NT mail servers.
How do I fix CVE-1999-0284?
To mitigate CVE-1999-0284, update your mail server software to the latest version that addresses this vulnerability.
Which software is affected by CVE-1999-0284?
CVE-1999-0284 affects NT mail servers, including IBM Lotus Domino Mail Server and Microsoft Exchange Server versions 4.0 and 5.0.
What type of vulnerability is CVE-1999-0284?
CVE-1999-0284 is a buffer overflow vulnerability that leads to denial of service.
Can CVE-1999-0284 be exploited remotely?
Yes, CVE-1999-0284 can be exploited remotely through the SMTP HELO command.