Enterprise LinuxOperating system · Redhat
CVE-2005-0091
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedUnknown vulnerability in the Red Hat Enterprise Linux 4 kernel 4GB/4GB split patch, when using the hugemem kernel, allows local users to read and write to arbitrary kernel memory and gain privileges via certain syscalls.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceVulnerability in the RHEL 4 kernel's 4GB/4GB split patch when running the hugemem kernel configuration allows local unprivileged users to read and write to arbitrary kernel memory, enabling privilege escalation to root via certain syscalls.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
Enterprise LinuxOperating system
= 4.0
Enterprise Linux DesktopOperating system
= 4.0CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Local
- Complexity
- Low
- Authentication
- None
- Confidentiality
- Complete
- Integrity
- Complete
- Availability
- Complete
AV:L/AC:L/Au:N/C:C/I:C/A:C
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify the RHEL versionRun 'cat /etc/redhat-release' or 'uname -r' to determine if the system is running RHEL 4.0Affected if The system is NOT running RHEL 4.0 or RHEL Desktop 4.0, then it is not affected by this specific CVE
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Check the running kernel configurationRun 'uname -a' or 'uname -r' to identify the kernel version string. The hugemem kernel typically contains 'hugemem' in the version name (e.g., 2.6.9-5.ELhugemem)Affected if The running kernel does NOT contain 'hugemem' in its name, the vulnerability does not apply because it is specific to the hugemem configuration
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Verify the 4GB/4GB split is in useCheck /proc/meminfo for total memory or examine kernel boot parameters in /boot/grub/grub.conf for '4gb' or 'split' references. The hugemem kernel implements a 4GB/4GB user/kernel splitAffected if The system is not using a hugemem kernel with the 4GB/4GB split, it is not vulnerable to this specific flaw
The system is affected only if it is RHEL 4.0 or RHEL Desktop 4.0 AND is running the hugemem kernel configuration with the 4GB/4GB split.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataApply the vendor-supplied kernel security update to address the vulnerability; if hugemem kernel is not required, consider switching to a non-vulnerable kernel configuration as a compensating control.
Fix this in Enterprise Linux
Scoped from the published advisory
- Consultation8.0 h
- Implementation4.0 h
- Testing16.0 h
- Review / QA8.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $9,856.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2005-0091 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2005-0091 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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