CVE-2003-1328Internet Explorer Vulnerability
The showHelp() function in Microsoft Internet Explorer 5.01, 5.5, and 6.0 supports certain types of pluggable protocols that allow remote attackers to bypass the cross-domain security model and execute arbitrary code, aka "Improper Cross Domain Security Validation with ShowHelp…
Published Feb 19, 2003 · Updated Apr 15, 2026
Key Facts
Patch immediately- CVE-2003-1328 is a high-severity vulnerability (CVSS 7.5 v2) affecting Ie (Microsoft), Internet Explorer (Microsoft).
- It is not listed in any known-exploited vulnerabilities catalog. Public exploit code is available.
- EPSS estimates a 39% probability of exploitation in the next 30 days.
- No fixed version is listed yet; check the vendor advisory for mitigations.
- Brandefense priority: patch immediately, because public exploit code exists for a high-severity flaw.
Scores
CVSS v2
7.5
AV:N/AC:L/Au:N/C:P/I:P/A:P
EPSS (30-day exploit likelihood)
39%
Higher than 98.5% of all scored CVEs
Exploit maturity
Proof of concept
ATLAS score
37/100
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
Proof of concept
Public exploit code
1
Proof-of-concept links
In-the-wild evidence
0
Reports of active use
Advisories And Exploit References
- advisoryie-showhelp-zone-bypass(11259)
Description
The showHelp() function in Microsoft Internet Explorer 5.01, 5.5, and 6.0 supports certain types of pluggable protocols that allow remote attackers to bypass the cross-domain security model and execute arbitrary code, aka "Improper Cross Domain Security Validation with ShowHelp functionality."
Affected Products
9 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| IeMicrosoft | 6.0-sp1 | n/a |
| Internet ExplorerMicrosoft | 5.0.1, 5.0.1-sp1, 5.0.1-sp2, 5.0.1-sp3, 5.5, 5.5-sp1, 5.5-sp2, 6.0 | n/a |
Timeline
Publicly disclosed
Feb 19, 2003
Last updated
Apr 15, 2026
References
- advisoryie-showhelp-zone-bypass(11259)
- exploitExploitDB-22226
- other20030206 showHelp("file:") disables security in IE - Sandblad advisory #11
- otherMS03-004
- otheroval:org.mitre.oval:def:57
FAQ
Common Questions.
The showHelp() function in Microsoft Internet Explorer 5.01, 5.5, and 6.0 supports certain types of pluggable protocols that allow remote attackers to bypass the cross-domain security model and execute arbitrary code, aka "Improper Cross Domain Security Validation with ShowHelp functionality."
Affected: Ie (Microsoft) versions 6.0-sp1; Internet Explorer (Microsoft) versions 5.0.1, 5.0.1-sp1, 5.0.1-sp2, 5.0.1-sp3, 5.5, 5.5-sp1, 5.5-sp2, 6.0. 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.
Public exploit code is available.
No fixed version is listed yet; check the vendor advisory for mitigations.
Brandefense priority: patch immediately, because public exploit code exists for a high-severity flaw.
Is CVE-2003-1328 On Your Attack Surface?
Brandefense matches it against the products discovered on your perimeter and opens a finding the day a CVE like this is listed.
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