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Debian LinuxOperating system · Debian

CVE-2018-5098

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
A use-after-free vulnerability can occur when form input elements, focus, and selections are manipulated by script content. This results 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

A use-after-free vulnerability exists in Firefox, Firefox ESR, and Thunderbird when script content manipulates form input elements, focus, and selections. The memory corruption occurs due to improper handling of these DOM manipulations, leading to a potentially exploitable crash that could allow arbitrary code execution.

MitigationUpgrade to Firefox 58+, Firefox ESR 52.6+, or Thunderbird 52.6+ to obtain the patched version that properly manages memory lifecycle of form input elements.

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:= 7.0= 8.0= 9.0
Enterprise Linux DesktopOperating system
Affected:= 6.0= 7.0
Enterprise Linux ServerOperating system
Affected:= 6.0= 7.0
Enterprise Linux Server AusOperating system
Affected:= 7.4
Enterprise Linux Server EusOperating system
Affected:= 7.4= 7.5
Enterprise Linux WorkstationOperating system
Affected:= 6.0= 7.0
FirefoxWeb browser
Affected:< 58.0< 52.6.0
Ubuntu LinuxOperating system
Affected:= 14.04= 16.04= 17.10

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 product and version
    Check if Firefox, Firefox ESR, or Thunderbird is installed. In Firefox, type 'about:support' in the address bar or go to Help > About. In Thunderbird, go to Help > About. Note the exact version number displayed.
    Affected if The product is Firefox < 58.0, Firefox ESR < 52.6.0, or Thunderbird < 52.6.0
  2. Confirm JavaScript is enabled
    In Firefox, type 'about:config' and search for 'javascript.enabled'. In Thunderbird, go to Options > Privacy & Security and check the 'Enable JavaScript' setting under Mail content (if available). Verify the setting is true/checked.
    Affected if JavaScript is enabled and the product version is in the affected range, as the exploit requires script content to manipulate form input elements

A user is affected if they run Firefox before 58.0, Firefox ESR before 52.6.0, or Thunderbird before 52.6.0, with JavaScript enabled, allowing script content to manipulate form input elements and trigger the use-after-free.

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

Upgrade to Firefox 58+, Firefox ESR 52.6+, or Thunderbird 52.6+ to obtain the patched version that properly manages memory lifecycle of form input elements.

Recommended fix High confidence

Firefox >= 58.0, Firefox ESR >= 52.6, Thunderbird >= 52.6

  1. 1. Identify which affected product is installed (Firefox, Firefox ESR, or Thunderbird)
  2. 2. For Firefox: Upgrade to version 58.0 or later (recommended: latest stable version)
  3. 3. For Firefox ESR: Upgrade to version 52.6 or later (recommended: latest ESR version)
  4. 4. For Thunderbird: Upgrade to version 52.6 or later (recommended: latest stable version)
  5. 5. On Linux systems, update via package manager: 'apt-get update && apt-get upgrade' (Debian/Ubuntu) or 'yum update' (RHEL/CentOS)
  6. 6. Verify the installed version matches or exceeds the fixed release (Firefox >= 58.0, Firefox ESR >= 52.6, Thunderbird >= 52.6)
  7. 7. Restart the application to ensure the update is fully applied
Caveat Minor: Some older Firefox extensions may be incompatible with Firefox 58+ due to WebExtension API changes; verify extension compatibility before deployment in production environments

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

Fix this in Debian Linux Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA4.0 h
22.0 hours of engineering $3,860
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,176.

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-2018-5098 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