CVE-2004-0751
MediumPublic exploitThe char_buffer_read function in the mod_ssl module for Apache 2.x, when using reverse proxying to an SSL server, allows remote attackers to cause a denial of service (segmentation fault).
Published Oct 20, 2004 · Updated Aug 4, 2026 · Also known as DEBIAN-CVE-2004-0751
Key Facts
Patch immediately- CVE-2004-0751 is a medium-severity vulnerability (CVSS 5.0 v2) affecting HTTP Server (Apache), apache2 (debian), rootio-apache2 and 1 more product.
- It is not listed in any known-exploited vulnerabilities catalog. Public exploit code is available.
- EPSS estimates a 72% probability of exploitation in the next 30 days.
- Fixed versions are available, including HTTP Server 2.0.51, apache2 2.0.50-11, httpd 0:2.0.46-40.ent.
- Brandefense priority: patch immediately, because it is very likely to be exploited soon.
CVSS v2
5.0
AV:N/AC:L/Au:N/C:N/I:N/A:P
EPSS (30-day exploit likelihood)
72%
Higher than 99.4% 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-2004-0751 brief as a PDF
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Description
The char_buffer_read function in the mod_ssl module for Apache 2.x, when using reverse proxying to an SSL server, allows remote attackers to cause a denial of service (segmentation fault).
Affected Products
15 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| HTTP ServerApache | See advisory | 2.0.51 |
| apache2debian | See advisory | 2.0.50-11 |
| rootio-apache2rootio | See advisory | 2.0.50-11 |
| httpdredhat | See advisory | 0:2.0.46-40.ent |
Patched Releases
HTTP Server
2.0.51
apache2
2.0.50-11
httpd
0:2.0.46-40.ent
rootio-apache2
2.0.50-11
Timeline
Publicly disclosed
Oct 20, 2004
Last updated
Aug 4, 2026
References
- advisoryRHSA-2004:463
- advisoryapache-modssl-speculative-dos(17273)
- advisoryoval:org.mitre.oval:def:11864
- advisoryhttps://security-tracker.debian.org/tracker/CVE-2004-0751
- advisoryGLSA-200409-21
FAQ
Common Questions.
The char_buffer_read function in the mod_ssl module for Apache 2.x, when using reverse proxying to an SSL server, allows remote attackers to cause a denial of service (segmentation fault).
Affected: HTTP Server (Apache); apache2 (debian); rootio-apache2, 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.
Fixed versions are available, including HTTP Server 2.0.51, apache2 2.0.50-11, httpd 0:2.0.46-40.ent.
Brandefense priority: patch immediately, because it is very likely to be exploited soon.
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