CVE-2004-0840

What it is

The SMTP (Simple Mail Transfer Protocol) component of Microsoft Windows XP 64-bit Edition, Windows Server 2003, Windows Server 2003 64-bit Edition, and the Exchange Routing Engine component of Exchange Server 2003, allows remote attackers to execute arbitrary code via a malicious DNS response message containing length values that are not properly validated.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of data exposure, data tampering, service disruption.

Exploit odds

30.2% chance of exploitation in the next 30 days (EPSS). Higher than most.

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2004-11-03 05:00 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-16 22:06 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 30.2% in the next 30 days (EPSS).
• Severity: 10.0 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2004-11-03 05:00 UTC

Last modified

2026-06-16 22:06 UTC

Exploit probability

30.2% · EPSS, next 30 days

Weakness

CWE-20 · Improper input validation

Record status

Modified

Affected

• Microsoft Exchange Server 2003
• Microsoft Windows Server 2003
• Microsoft Windows Server 2003 r2
• Microsoft Windows Xp

Attack profile CVSS 2.0 · 10.0

Attack vector

Network

Complexity

Low

Authentication

None

Confidentiality

Complete

Integrity

Complete

Availability

Complete

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2004-0840.md and follow it. Check whether this project is affected by CVE-2004-0840. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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