CVE-2004-0840Exchange Server Vulnerability
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…
Published Nov 3, 2004 · Updated Apr 15, 2026
Key Facts
Patch in the next maintenance window- CVE-2004-0840 is a critical-severity vulnerability (CVSS 10.0 v2) affecting Exchange Server (Microsoft), Windows Server 2003 (Microsoft), Windows Xp (Microsoft).
- It is not listed in any known-exploited vulnerabilities catalog. No public exploit code is known.
- EPSS estimates a 30% probability of exploitation in the next 30 days.
- No fixed version is listed yet; check the vendor advisory for mitigations.
- Brandefense priority: patch in the next maintenance window, because of its high severity, although no exploitation is known.
Scores
CVSS v2
10.0
AV:N/AC:L/Au:N/C:C/I:C/A:C
EPSS (30-day exploit likelihood)
30%
Higher than 98.2% of all scored CVEs
Exploit maturity
None known
ATLAS score
41/100
Publication score, see How it works
Exploitation Verdict
KEV listed
Not listed
Federal due date
None
No federal due date
Ransomware use
Not reported
Attributed actors
None named
Exploit & Defence Guidance
Exploit maturity
None known
Public exploit code
0
Proof-of-concept links
In-the-wild evidence
0
Reports of active use
Advisories And Exploit References
- advisorywin2k3-smtp-execute-code(17621)
- advisorywin-ms04035-patch(17660)
- advisoryoval:org.mitre.oval:def:2300
- advisoryoval:org.mitre.oval:def:3460
- advisoryoval:org.mitre.oval:def:5509
- advisory11374
Description
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.
Affected Products
4 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| Exchange ServerMicrosoft | 2003 | n/a |
| Windows Server 2003Microsoft | r2 | n/a |
| Windows XpMicrosoft | See advisory | n/a |
Timeline
Publicly disclosed
Nov 3, 2004
Last updated
Apr 15, 2026
Weakness Type
- CWE-20 Improper Input Validation
References
- advisorywin2k3-smtp-execute-code(17621)
- advisorywin-ms04035-patch(17660)
- advisoryoval:org.mitre.oval:def:2300
- advisoryoval:org.mitre.oval:def:3460
- advisoryoval:org.mitre.oval:def:5509
FAQ
Common Questions.
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…
Affected: Exchange Server (Microsoft) versions 2003; Windows Server 2003 (Microsoft) versions r2; Windows Xp (Microsoft). The full list is in the CVE brief.
It is not listed in any known-exploited vulnerabilities catalog.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
No public exploit code is known.
No fixed version is listed yet; check the vendor advisory for mitigations.
Brandefense priority: patch in the next maintenance window, because of its high severity, although no exploitation is known.
Is CVE-2004-0840 On Your Attack Surface?
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