Ubuntu LinuxOperating system · Canonical
CVE-2016-2841
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 · uneditedThe ne2000_receive function in the NE2000 NIC emulation support (hw/net/ne2000.c) in QEMU before 2.5.1 allows local guest OS administrators to cause a denial of service (infinite loop and QEMU process crash) via crafted values for the PSTART and PSTOP registers, involving ring buffer control.
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 confidenceThe ne2000_receive function in QEMU's NE2000 NIC emulation lacks proper validation of PSTART and PSTOP register values controlling the ring buffer. A malicious guest OS administrator can set these registers to cause an infinite loop in the receive path, resulting in QEMU process crash and denial of service.
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
Ubuntu LinuxOperating system
= 12.04= 14.04= 15.10= 16.04<= 2.5.0CVSS 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
- Privileges
- High
- User interaction
- None
- Scope
- Changed
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:H
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 QEMU versionRun 'qemu-system-x86_64 --version' or 'qemu-system-i386 --version' to determine the installed QEMU version numberAffected if The version is 2.5.0 or lower, indicating the lack of bounds checking on PSTART/PSTOP registers
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Locate running QEMU processes using NE2000 emulationInspect VM configuration files or running processes for '-net nic,model=ne2k_pci' or similar NE2000 device parametersAffected if A VM is configured with the ne2k_pci (NE2000) network interface model
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Verify NE2000 ring buffer configuration capabilityIf using NE2000, check whether the guest OS has administrative control to set PSTART and PSTOP registers (these control the receive ring buffer boundaries)Affected if A malicious or compromised guest administrator can manipulate these registers to trigger the infinite loop condition in the ne2000_receive function
A system is affected if it runs QEMU version 2.5.0 or lower with an active NE2000 (ne2k_pci) virtual network interface, allowing a guest to trigger the unbounded loop via PSTART/PSTOP register manipulation.
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 dataUpgrade QEMU to version 2.5.1 or later which contains proper bounds checking on the ring buffer register values.
Fix this in Ubuntu Linux
Scoped from the published advisory
- Consultation2.0 h
- Implementation4.0 h
- Testing6.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,808.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2016-2841 — 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-2016-2841 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
- No weaponised exploit code, or anything meant to cause harm
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