CVE-1999-0393

Sendmail 8.8.x and 8.9.2 - Denial of Service via Large Number of Headers

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-1999-0393. PoCs published by marchew.

AI-analyzed exploit summary This exploit targets a denial-of-service (DoS) vulnerability in Sendmail versions up to 8.9.2 by flooding the SMTP service with excessive data. It forks multiple connections to the target host and sends a large number of 'To:' headers to exhaust system resources.

Description

Remote attackers can cause a denial of service in Sendmail 8.8.x and 8.9.2 by sending messages with a large number of headers.

Exploits (1)

exploitdb WORKING POC VERIFIED
by marchew · cdosirix
https://www.exploit-db.com/exploits/23167

This exploit targets a denial-of-service (DoS) vulnerability in Sendmail versions up to 8.9.2 by flooding the SMTP service with excessive data. It forks multiple connections to the target host and sends a large number of 'To:' headers to exhaust system resources.

Classification
Working Poc 95%
Attack Type
Dos
Complexity
Trivial
Reliability
Reliable
Target: Sendmail up to 8.9.2
No auth needed
Prerequisites: Network access to the target SMTP port (25) · Valid username on the target system
devstral-2 · analyzed Feb 16, 2026 Full analysis →

References (1)

Core 1
Core References
Mailing List mailing-list x_refsource_bugtraq
http://marc.info/?l=bugtraq&m=91694391227372&w=2

Scores

EPSS 0.0243
EPSS Percentile 82.2%

Details

Status published
Products (2)
eric_allman/sendmail 8.8
eric_allman/sendmail 8.9.2
Published Jan 01, 1999
Tracked Since Feb 18, 2026