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QemuApplication

CVE-2015-8556

CRITICAL · 10.0 CVSS v3.0 Published 2017-03-24
Fix available
A fix is available. Upgrade to after 2.4.1 or later.
See remediation →
100/100
Remediation priority · Urgent
Public exploit 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
Local privilege escalation vulnerability in the Gentoo QEMU package before 2.5.0-r1.

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 confidence

Local privilege escalation vulnerability in Gentoo's QEMU package before version 2.5.0-r1, allowing an unprivileged user to gain root access on the host system.

MitigationUpgrade Gentoo QEMU package to version 2.5.0-r1 or later; if immediate patching is not feasible, restrict QEMU access to trusted users and monitor for unauthorized access attempts.

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
QemuApplication
Affected:<= 2.4.1

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
Privileges
None
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/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 checks

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

  1. Confirm Gentoo Linux distribution
    Check if the system is Gentoo by examining /etc/gentoo-release or running 'uname -a' to see if it shows gentoo
    Affected if System is not Gentoo - this specific vulnerability affects only Gentoo's QEMU package distribution
  2. Check if QEMU is installed via Gentoo Portage
    Run 'emerge --search qemu' or 'equery list qemu' to see if QEMU packages are installed using Gentoo's package manager
    Affected if QEMU is not installed via Portage - the vulnerability is in Gentoo's packaged version of QEMU
  3. Identify the exact Qemu Qemu package version
    Run 'emerge -av qemu' or 'equery list Qemu-Qemu' to display the installed version of the specific Qemu Qemu package
    Affected if The package is not installed - this specific package must be present for the flaw to apply
  4. Compare installed version against affected range
    Examine the version number from the previous step and compare it to the affected versions: any version of Qemu Qemu <= 2.4.1
    Affected if Installed version is 2.4.1 or lower, or the version does not show 2.5.0-r1 or later

A Gentoo system is affected if it has the Qemu Qemu package installed with a version of 2.4.1 or lower (versions prior to 2.5.0-r1).

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.

dbcve · scoped
Upgrade available Upgrade to a release after 2.4.1
Interim mitigation

Upgrade Gentoo QEMU package to version 2.5.0-r1 or later; if immediate patching is not feasible, restrict QEMU access to trusted users and monitor for unauthorized access attempts.

Recommended fix High confidence

QEMU 2.5.0-r1 or later (Gentoo) / QEMU 2.5.0 or later (upstream)

  1. 1. Ensure you have root privileges on the Gentoo system
  2. 2. Sync the Gentoo package repository: `emerge --sync` or `eix-sync`
  3. 3. Update the QEMU package to version 2.5.0-r1 or later: `emerge --update app-emulation/qemu`
  4. 4. If specific QEMU variants are installed (e.g., qemu-user, qemu-system-x86_64), update those as well: `emerge --update app-emulation/qemu app-emulation/qemu-user`
  5. 5. Rebuild any packages that may depend on QEMU if needed: `emerge --deep --newuse @world`
  6. 6. Reboot the system if QEMU is running as a service or if kernel modules were updated
Caveat Major version upgrades of QEMU may require updating VM configurations, disk image formats, or guest tooling; test in a non-production environment first

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Qemu Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA1.0 h
10.0 hours of engineering $1,750
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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-2015-8556 in production — separate from our analysis above.

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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