CVE-2004-0842
HighPublic exploitInternet Explorer 6.0 SP1 and earlier, and possibly other versions, allows remote attackers to cause a denial of service (application crash from "memory corruption") via certain malformed Cascading Style Sheet (CSS) elements that trigger heap-based buffer overflows, as…
Published Dec 23, 2004 · Updated Apr 15, 2026
Key Facts
Patch immediately- CVE-2004-0842 is a high-severity vulnerability (CVSS 7.5 v2) affecting Ip600 Media Servers (Avaya), Ie (Microsoft), Internet Explorer (Microsoft) and 4 more products.
- It is not listed in any known-exploited vulnerabilities catalog. Public exploit code is available.
- EPSS estimates a 57% 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 it is very likely to be exploited soon.
CVSS v2
7.5
AV:N/AC:L/Au:N/C:P/I:P/A:P
EPSS (30-day exploit likelihood)
57%
Higher than 99.0% of all scored CVEs
Exploited in the wild
No known
Not in a known-exploited catalog
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2004-0842 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
Description
Internet Explorer 6.0 SP1 and earlier, and possibly other versions, allows remote attackers to cause a denial of service (application crash from "memory corruption") via certain malformed Cascading Style Sheet (CSS) elements that trigger heap-based buffer overflows, as demonstrated using the "@;/*" string, possibly due to a missing comment terminator that may cause an invalid length to trigger a large memory copy operation, aka the "CSS Heap Memory Corruption Vulnerability."
Affected Products
16 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| Ip600 Media ServersAvaya | See advisory | n/a |
| IeMicrosoft | 6.0-sp1 | n/a |
| Internet ExplorerMicrosoft | 5.0.1, 5.0.1-sp1, 5.0.1-sp2, 5.0.1-sp3, 5.0.1-sp4, 5.5, 5.5-sp1, 5.5-sp2 | n/a |
| Definity One Media ServerAvaya | See advisory | n/a |
| S3400Avaya | See advisory | n/a |
Timeline
Publicly disclosed
Dec 23, 2004
Last updated
Apr 15, 2026
References
- patch10816
- exploitExploitDB-24328
- exploithttp://www.ecqurity.com/adv/IEstyle.html
- other20040728 Re: Crash IE with 11 bytes ;)
- other20040723 Crash IE with 11 bytes ;)
FAQ
Common Questions.
Internet Explorer 6.0 SP1 and earlier, and possibly other versions, allows remote attackers to cause a denial of service (application crash from "memory corruption") via certain malformed Cascading Style Sheet (CSS) elements that trigger heap-based buffer overflows, as demonstrated using the "@;/*" string, possibly du…
Affected: Ip600 Media Servers (Avaya); 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, 5.0.1-sp4, 5.5, 5.5-sp1, 5.5-sp2, among others. 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 it is very likely to be exploited soon.
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