dbcve.org
Enterprise Linux DesktopOperating system · Redhat

CVE-2018-12364

HIGH · 8.8 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 →
95/100
Remediation priority · Urgent
Remotely reachable No privileges

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
NPAPI plugins, such as Adobe Flash, can send non-simple cross-origin requests, bypassing CORS by making a same-origin POST that does a 307 redirect to the target site. This allows for a malicious site to engage in cross-site request forgery (CSRF) attacks. This vulnerability affects Thunderbird < 60, Thunderbird < 52.9, Firefox ESR < 60.1, Firefox ESR < 52.9, and Firefox < 61.

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

NPAPI plugins (e.g., Adobe Flash) can bypass CORS protections by initiating a same-origin POST request that performs a 307 redirect to a cross-origin target. This allows malicious sites to conduct CSRF attacks by tricking browsers into sending authenticated cross-site requests that bypass normal CORS restrictions.

MitigationUpdate affected software to Thunderbird 60+, Firefox ESR 60.1+/52.9+, or Firefox 61+ to receive the CORS bypass patch. Consider disabling or removing NPAPI plugins 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
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= 17.10= 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
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.0/AV:N/AC:L/PR:N/UI:R/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 browser application
    Open the browser and navigate to Help > About (Firefox or Thunderbird) to view the installed version number
    Affected if The browser is Firefox or Thunderbird and the version is older than the patched releases (Firefox 61+, Firefox ESR 52.9+, Thunderbird 60+)
  2. Check for NPAPI plugin support enabled
    In Firefox, type about:config in the address bar and search for 'plugin.enable' or navigate to Add-ons > Plugins to see if NPAPI plugins (such as Adobe Flash) are listed and enabled
    Affected if NPAPI plugins are present and enabled in the browser configuration
  3. Verify if Flash or other NPAPI plugins are installed
    In Firefox, navigate to about:addons and view the Plugins section, or check for the presence of the Flash plugin file (nppdf32.dll on Windows, libflashplayer.so on Linux) in the browser's plugin directory
    Affected if Adobe Flash or other NPAPI plugins are installed and active in the browser
  4. Confirm browser is used for web requests
    Check if the affected browser (Firefox or Thunderbird) is used as the default system browser or regularly used for browsing websites that could serve malicious content
    Affected if The vulnerable browser version is actively used for web browsing

The environment is affected if Firefox or Thunderbird version is older than the patched releases (Firefox 61+, Firefox ESR 52.9+, Thunderbird 60+) AND NPAPI plugins like Adobe Flash are enabled in the browser.

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.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Update affected software to Thunderbird 60+, Firefox ESR 60.1+/52.9+, or Firefox 61+ to receive the CORS bypass patch. Consider disabling or removing NPAPI plugins as a defense-in-depth measure.

Fix this in Enterprise Linux Desktop Scoped from the published advisory
  • Consultation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
5.0 hours of engineering $880
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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-2018-12364 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