dbcve.org
Enterprise Linux DesktopOperating system · Redhat

CVE-2018-12377

CRITICAL · 9.8 CVSS v3.0 Published 2018-10-18
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
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
A use-after-free vulnerability can occur when refresh driver timers are refreshed in some circumstances during shutdown when the timer is deleted while still in use. This results in a potentially exploitable crash. This vulnerability affects Firefox < 62, Firefox ESR < 60.2, and Thunderbird < 60.2.1.

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

A use-after-free vulnerability exists in the refresh driver timer mechanism where timers are deleted while still in use during application shutdown, causing a crash that could potentially be exploited for arbitrary code execution.

MitigationUpgrade to Firefox 62+, Firefox ESR 60.2+, or Thunderbird 60.2.1+ to patch the timer management flaw in the refresh driver.

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
Enterprise Linux DesktopOperating system
Affected:= 6.0= 7.0
Enterprise Linux ServerOperating system
Affected:= 6.0= 7.0
Enterprise Linux Server AusOperating system
Affected:= 7.6
Enterprise Linux Server EusOperating system
Affected:= 7.5= 7.6
Enterprise Linux Server TusOperating system
Affected:= 7.6
Enterprise Linux WorkstationOperating system
Affected:= 6.0= 7.0
Debian LinuxOperating system
Affected:= 8.0= 9.0
Ubuntu LinuxOperating system
Affected:= 14.04= 16.04= 18.04

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. Identify installed Mozilla products
    Run 'rpm -qa | grep -i firefox' for RHEL/CentOS, 'dpkg -l | grep -i firefox' for Debian/Ubuntu, or check Thunderbird with 'rpm -qa | grep -i thunderbird' / 'dpkg -l | grep -i thunderbird'
    Affected if Firefox or Thunderbird is installed on the system
  2. Get Firefox version
    Run 'firefox --version' or check the package version via 'rpm -q firefox' / 'dpkg -s firefox'
    Affected if Version is earlier than 62.0 for standard Firefox, or earlier than 60.2 for Firefox ESR
  3. Get Thunderbird version
    Run 'thunderbird --version' or check the package version via 'rpm -q thunderbird' / 'dpkg -s thunderbird'
    Affected if Version is earlier than 60.2.1 for Thunderbird

The system is affected if Firefox versions below 62.0 (or ESR below 60.2) or Thunderbird versions below 60.2.1 are installed and the application uses the refresh driver timer functionality.

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
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade to Firefox 62+, Firefox ESR 60.2+, or Thunderbird 60.2.1+ to patch the timer management flaw in the refresh driver.

Recommended fix High confidence

Firefox 62+, Firefox ESR 60.2+, or Thunderbird 60.2.1+

  1. Identify which application is affected: Firefox, Firefox ESR, or Thunderbird
  2. For Red Hat Enterprise Linux systems, update the affected package using: yum update firefox OR yum update thunderbird
  3. For Debian systems, update using: apt-get update && apt-get install firefox or apt-get install thunderbird
  4. For Ubuntu systems, update using: apt-get update && apt-get install firefox or apt-get install thunderbird
  5. After updating, verify the installed version matches or exceeds: Firefox 62, Firefox ESR 60.2, or Thunderbird 60.2.1
  6. Restart the application to ensure the fixed version is loaded
Caveat None expected - this is a security update to stable release versions

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

Fix this in Enterprise Linux Desktop Scoped from the published advisory
  • Consultation1.0 h
  • Implementation2.0 h
  • Testing1.0 h
  • Review / QA1.0 h
5.0 hours of engineering $890
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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-2018-12377 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