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Debian LinuxOperating system · Debian

CVE-2018-5095

CRITICAL · 9.8 CVSS v3.0 Published 2018-06-11
Fix available
A fix is available. Upgrade to 52.6.0 / 58.0 or later.
See remediation →
100/100
Remediation priority · Urgent
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
An integer overflow vulnerability in the Skia library when allocating memory for edge builders on some systems with at least 8 GB of RAM. This results in the use of uninitialized memory, resulting in a potentially exploitable crash. This vulnerability affects Thunderbird < 52.6, Firefox ESR < 52.6, and Firefox < 58.

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

Integer overflow in Skia library's memory allocation for edge builders on systems with 8GB+ RAM. The overflow causes undersized buffer allocation, leading to use of uninitialized memory and potentially exploitable crashes with remote code execution possibility.

MitigationUpdate affected Mozilla products (Firefox < 58, Firefox ESR < 52.6, Thunderbird < 52.6) to patched versions. For legacy systems that cannot update, consider network-level isolation and disable JavaScript as a defense-in-depth measure.

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
Debian LinuxOperating system
Affected:= 8.0= 9.0
Enterprise LinuxOperating system
Affected:= 6.0= 7.0
Enterprise Linux DesktopOperating system
Affected:= 6.0= 7.0
Enterprise Linux ServerOperating system
Affected:= 6.0= 7.0
Enterprise Linux Server AusOperating system
Affected:= 7.3= 7.4
Enterprise Linux Server EusOperating system
Affected:= 7.3= 7.4= 7.5
Enterprise Linux WorkstationOperating system
Affected:= 6.0= 7.0
FirefoxWeb browser
Affected:< 58.0< 52.6.0

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

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/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. Check installed Firefox version
    Run 'firefox --version' or check the package manager (dpkg -l firefox or rpm -qi firefox)
    Affected if Version is less than 58.0 or between 52.6.0 and 57.x (note: 52.6.0+ is fixed)
  2. Check installed Thunderbird version
    Run 'thunderbird --version' or check the package manager (dpkg -l thunderbird or rpm -qi thunderbird)
    Affected if Version is less than 52.6.0
  3. Check system RAM
    Run 'free -h' or 'cat /proc/meminfo | grep MemTotal'
    Affected if System has 8GB or more of RAM (the overflow condition requires 8GB+ RAM to trigger)
  4. Verify Skia library presence
    Check for libskia in browser directory: 'find /usr -name "*skia*" 2>/dev/null' or check browser's about:support for Skia version
    Affected if Skia library is loaded and browser version is vulnerable per above checks

User is affected if using Firefox < 58.0 or Thunderbird < 52.6.0 on a system with 8GB+ RAM where the Skia library handles graphic rendering.

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 52.6.0 / 58.0 or later
Fixed in 52.6.058.0
Interim mitigation

Update affected Mozilla products (Firefox < 58, Firefox ESR < 52.6, Thunderbird < 52.6) to patched versions. For legacy systems that cannot update, consider network-level isolation and disable JavaScript as a defense-in-depth measure.

Recommended fix High confidence

Upgrade to Firefox 58.0+, Firefox ESR 52.6.0+, or Thunderbird 52.6.0+ (depending on which product is affected)

  1. Identify the affected application (Firefox, Firefox ESR, or Thunderbird) installed on the system
  2. For RHEL/CentOS systems: Run 'yum update firefox' or 'yum update thunderbird' to fetch and install the fixed packages from vendor repositories
  3. For Debian/Ubuntu systems: Run 'apt-get update && apt-get install firefox-esr' or 'apt-get install thunderbird' to get the patched version
  4. Verify the installed version matches the fixed release (Firefox >= 58.0, Firefox ESR >= 52.6.0, Thunderbird >= 52.6.0) by running 'firefox --version' or 'thunderbird --version'
  5. Restart any running browser or email client instances to ensure the patched version is in use
Caveat Upgrading Firefox may reset some browser settings and extensions; ESR version upgrades typically maintain settings but verify compatibility of any enterprise policies

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

Fix this in Debian Linux Scoped from the published advisory
  • Consultation1.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,040
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,664.

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-2018-5095 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