How severe is CVE-2004-0203?

CVE-2004-0203 has a CVSS 2.0 base score of 4.3, rated medium severity.

Is CVE-2004-0203 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 21% (97th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2004-0203?

CVE-2004-0203 primarily affects Microsoft Exchange Server. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2004-0203?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2004-0203 published?

CVE-2004-0203 was published on 2004-11-23 and last updated on 2026-06-16.

CVE-2004-0203

CVE-2004-0203 is a medium-severity vulnerability in Microsoft Exchange Server with a CVSS 2.0 base score of 4.3. Its EPSS exploit-prediction score of 21% places it in the 97th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-79.

Key facts

Severity: Medium (CVSS 2.0 base score 4.3)
EPSS exploit prediction: 21% (97th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Microsoft Exchange Server
Published: 2004-11-23
Last modified: 2026-06-16

Description

Cross-site scripting (XSS) vulnerability in Outlook Web Access for Exchange Server 5.5 Service Pack 4 allows remote attackers to insert arbitrary script and spoof content in HTML email or web caches via an HTML redirect query.

Frequently asked questions

What is CVE-2004-0203?: Cross-site scripting (XSS) vulnerability in Outlook Web Access for Exchange Server 5.5 Service Pack 4 allows remote attackers to insert arbitrary script and spoof content in HTML email or web caches via an HTML redirect query.
How severe is CVE-2004-0203?: CVE-2004-0203 has a CVSS 2.0 base score of 4.3, rated medium severity.
Is CVE-2004-0203 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 21% (97th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2004-0203?: CVE-2004-0203 primarily affects Microsoft Exchange Server. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2004-0203?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2004-0203 published?: CVE-2004-0203 was published on 2004-11-23 and last updated on 2026-06-16.

References

Affected products (5)

cpe:2.3:a:microsoft:exchange_server:5.5:-:*:*:*:*:*:*
cpe:2.3:a:microsoft:exchange_server:5.5:sp1:*:*:*:*:*:*
cpe:2.3:a:microsoft:exchange_server:5.5:sp2:*:*:*:*:*:*
cpe:2.3:a:microsoft:exchange_server:5.5:sp3:*:*:*:*:*:*
cpe:2.3:a:microsoft:exchange_server:5.5:sp4:*:*:*:*:*:*

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