CVE-2016-2538
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 · uneditedMultiple integer overflows in the USB Net device emulator (hw/usb/dev-network.c) in QEMU before 2.5.1 allow local guest OS administrators to cause a denial of service (QEMU process crash) or obtain sensitive host memory information via a remote NDIS control message packet that is mishandled in the (1) rndis_query_response, (2) rndis_set_response, or (3) usb_net_handle_dataout function.
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 confidenceInteger overflow vulnerabilities in QEMU's USB network device emulator (dev-network.c) allow a malicious guest administrator to send specially crafted NDIS control message packets that overflow buffers, potentially leaking sensitive host memory or causing a QEMU process crash.
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<= 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
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- High
CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/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 installed QEMU versionRun `qemu-system-x86_64 --version` or `qemu --version` depending on your QEMU installation method. Also check package manager output with `dpkg -l | grep qemu` (Debian) or `rpm -qa | grep qemu` (RHEL).Affected if The version is 2.5.0 or lower.
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Identify all running QEMU processes with USB network devicesUse `ps aux | grep qemu` to list running QEMU instances, then examine their command-line arguments for USB network device configuration such as `-net usb` or `-device usb-net` parameters.Affected if A running QEMU process has USB network device emulation enabled via command-line arguments.
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Check for USB network device passthrough configuration in VM definitionsIf using libvirt, inspect VM XML definitions with `virsh dumpxml <vm-name>` and search for `<hostdev>` entries with USB network device vendor/product IDs, or `<interface type='usb'>` elements.Affected if A VM definition includes USB network device passthrough configuration.
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Verify if USB host device assignment is permittedCheck libvirt configuration with `virsh nwfilter-list` and examine USB device assignment policies in `/etc/libvirt/qemu.conf` or `/etc/libvirt/hooks` for any USB device allowlisting.Affected if USB device passthrough to guests is allowed in the configuration.
A system is affected if it runs QEMU version 2.5.0 or earlier AND has USB network device emulation enabled or USB network devices passed through to guest virtual machines.
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. If upgrading is not immediately possible, restrict USB network device passthrough to trusted guests and monitor for QEMU crashes.
- Consultation3.0 h
- Implementation6.0 h
- Testing5.0 h
- Review / QA3.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,752.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2016-2538 — 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-2016-2538 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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