How severe is CVE-2003-0521?

CVE-2003-0521 has a CVSS 2.0 base score of 6.8, rated medium severity.

Is CVE-2003-0521 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (74th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2003-0521?

CVE-2003-0521 primarily affects Cpanel. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2003-0521?

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

When was CVE-2003-0521 published?

CVE-2003-0521 was published on 2003-08-18 and last updated on 2026-06-16.

CVE-2003-0521

CVE-2003-0521 is a medium-severity vulnerability in Cpanel with a CVSS 2.0 base score of 6.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: Medium (CVSS 2.0 base score 6.8)
EPSS exploit prediction: 2% (74th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Cpanel
Published: 2003-08-18
Last modified: 2026-06-16

Description

Cross-site scripting (XSS) vulnerability in cPanel 6.4.2 allows remote attackers to insert arbitrary HTML and possibly gain cPanel administrator privileges via script in a URL that is logged but not properly quoted when displayed via the (1) Error Log or (2) Latest Visitors screens.

Frequently asked questions

What is CVE-2003-0521?: Cross-site scripting (XSS) vulnerability in cPanel 6.4.2 allows remote attackers to insert arbitrary HTML and possibly gain cPanel administrator privileges via script in a URL that is logged but not properly quoted when displayed via the (1) Error Log or (2) Latest Visitors screens.
How severe is CVE-2003-0521?: CVE-2003-0521 has a CVSS 2.0 base score of 6.8, rated medium severity.
Is CVE-2003-0521 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (74th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2003-0521?: CVE-2003-0521 primarily affects Cpanel. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2003-0521?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2003-0521 published?: CVE-2003-0521 was published on 2003-08-18 and last updated on 2026-06-16.

References

http://marc.info/?l=bugtraq&m=105760556627616&w=2

Affected products (8)

cpe:2.3:a:cpanel:cpanel:5.0:*:*:*:*:*:*:*
cpe:2.3:a:cpanel:cpanel:5.3:*:*:*:*:*:*:*
cpe:2.3:a:cpanel:cpanel:6.0:*:*:*:*:*:*:*
cpe:2.3:a:cpanel:cpanel:6.2:*:*:*:*:*:*:*
cpe:2.3:a:cpanel:cpanel:6.4:*:*:*:*:*:*:*
cpe:2.3:a:cpanel:cpanel:6.4.1:*:*:*:*:*:*:*
cpe:2.3:a:cpanel:cpanel:6.4.2:*:*:*:*:*:*:*
cpe:2.3:a:cpanel:cpanel:6.4.2_stable_48:*:*:*:*:*:*:*

More vulnerabilities in Cpanel

CVE-2004-1770 — Critical (CVSS 10.0): The login page for cPanel 9.1.0, and possibly other versions, allows remote attackers to execute arbitrary code via…
CVE-2004-1769 — Critical (CVSS 10.0): The "Allow cPanel users to reset their password via email" feature in cPanel 9.1.0 build 34 and earlier, including 8.x,…
CVE-2003-1425 — Critical (CVSS 10.0): guestbook.cgi in cPanel 5.0 allows remote attackers to execute arbitrary commands via the template parameter.
CVE-2026-41940 — Critical (CVSS 9.8): cPanel and WHM versions after 11.40 contain an authentication bypass vulnerability in the login flow that allows…
CVE-2020-26108 — Critical (CVSS 9.8): cPanel before 88.0.13 mishandles file-extension dispatching, leading to code execution (SEC-488).
CVE-2020-26105 — Critical (CVSS 9.8): In cPanel before 88.0.3, insecure chkservd test credentials are used on a templated VM (SEC-554).

All CVEs affecting Cpanel →