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Linux KernelOperating system · Linux

CVE-2009-4536

HIGH · 7.8 CVSS v2.0 Published 2010-01-12
Fix available
A fix is available. Upgrade to after 2.6.32.3 or later.
See remediation →
87/100
Remediation priority · High
Remotely reachable No privileges Zero-click

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 · unedited
drivers/net/e1000/e1000_main.c in the e1000 driver in the Linux kernel 2.6.32.3 and earlier handles Ethernet frames that exceed the MTU by processing certain trailing payload data as if it were a complete frame, which allows remote attackers to bypass packet filters via a large packet with a crafted payload. NOTE: this vulnerability exists because of an incorrect fix for CVE-2009-1385.

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 · high confidence

The e1000 network driver in Linux kernel 2.6.32.3 and earlier incorrectly processes trailing payload data from Ethernet frames that exceed the MTU as if it were a complete frame. This allows remote attackers to bypass packet filters by sending large packets with crafted payloads. The flaw is an incomplete fix for CVE-2009-1385.

MitigationUpdate the Linux kernel to a version that contains the corrected e1000 driver fix, or apply the vendor-supplied patch for this vulnerability.

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
Linux KernelOperating system
Affected:<= 2.6.32.3
Debian LinuxOperating system
Affected:= 4.0= 5.0

CVSS 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
Network
Complexity
Low
Authentication
None
Confidentiality
None
Integrity
None
Availability
Complete

AV:N/AC:L/Au:N/C:N/I:N/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 checks

Work through these to decide whether this CVE applies to you.

  1. Check installed kernel version
    Run 'uname -r' or 'cat /proc/version' to obtain the kernel version number
    Affected if The kernel version is 2.6.32.3 or earlier (2.6.x series where x <= 32)
  2. Identify if e1000 driver is loaded
    Run 'lsmod | grep e1000' or check '/proc/modules' to see if the e1000 kernel module is currently loaded
    Affected if The e1000 module appears in the loaded modules list
  3. Determine if any network interface uses e1000
    Run 'ethtool -i <interface>' for each ethernet interface (e.g., eth0, eth1) or check 'lspci | grep Ethernet' to list e1000 network controllers
    Affected if Any network interface is bound to the e1000 driver
  4. Verify oversized packet handling (optional diagnostic)
    Capture network traffic with tcpdump or wireshark and observe if frames larger than the configured MTU are being processed as complete frames rather than being fragmented or dropped
    Affected if Oversized packets (greater than MTU) are being accepted and processed as valid complete frames by the e1000 interface

You are affected if your system runs Linux kernel 2.6.32.3 or earlier and has an active network interface using the e1000 driver, allowing oversized Ethernet frames to bypass packet filters.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 data
Upgrade available Upgrade to a release after 2.6.32.3
Interim mitigation

Update the Linux kernel to a version that contains the corrected e1000 driver fix, or apply the vendor-supplied patch for this vulnerability.

Fix this in Linux Kernel Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,930
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Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2009-4536 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data