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CVE-2018-12395· NVD / CVE Program· CNA mozilla

By rewriting the Host: request headers using the webRequest API, a WebExtension can bypass domain restrictions through domain fronting.

Noroxi assessment

Priority: Monitor (action score 31/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 2.8% (FIRST EPSS); higher than 86.6% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: firefox-esr (Debian:12) 60.3.0esr-1; firefox-esr (Debian:8) 60.3.0esr-1~deb8u1; firefox-esr (Debian:9) 60.3.0esr-1~deb9u1.

Low priority for now. Upgrade to firefox-esr (Debian:12) 60.3.0esr-1; firefox-esr (Debian:8) 60.3.0esr-1~deb8u1; firefox-esr (Debian:9) 60.3.0esr-1~deb9u1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

By rewriting the Host: request headers using the webRequest API, a WebExtension can bypass domain restrictions through domain fronting. This would allow access to domains that share a host that are otherwise restricted. This vulnerability affects Firefox ESR < 60.3 and Firefox < 63.

HighCVSS 7.5 · v3.0—No exploit Fix available
Published
Feb 28, 2019
Updated
Jun 16, 2026
EPSS
2.8% · 86th percentile
CWE
—

Report tools

JSON

Action score

31

Monitor

Low priority for now.

CVSS
30 / 40 · 7.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
1 / 30 · 2.8%

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2018-12395

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
mozillafirefox
mozillafirefox esr
debiandebian linux
canonicalubuntu linux
redhatenterprise linux desktop
redhatenterprise linux server
redhatenterprise linux server eus
redhatenterprise linux workstation

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • canonical ubuntu linux14.04
  • canonical ubuntu linux16.04
  • canonical ubuntu linux18.04
  • canonical ubuntu linux18.10
  • debian debian linux8.0
  • debian debian linux9.0
  • mozilla firefoxbefore 63.0
  • mozilla firefox esrbefore 60.3
  • redhat enterprise linux desktop6.0
  • redhat enterprise linux desktop7.0
  • redhat enterprise linux server6.0
  • redhat enterprise linux server7.0
  • redhat enterprise linux server eus7.5
  • redhat enterprise linux workstation6.0
  • redhat enterprise linux workstation7.0

Versions reported by the vendor

Affected version ranges reported by the assigning authority (mozilla). Independent of NVD's CPE analysis and usually ahead of it.

  • Mozilla Firefox

    • unspecified and later · before 63affected

  • Mozilla Firefox ESR

    • unspecified and later · before 60.3affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12firefox-esrbefore 60.3.0esr-160.3.0esr-1
Debian:8firefox-esrbefore 60.3.0esr-1~deb8u160.3.0esr-1~deb8u1
Debian:9firefox-esrbefore 60.3.0esr-1~deb9u160.3.0esr-1~deb9u1
Red Hat:enterprise_linux:6::clientfirefoxbefore 0:60.3.0-1.el60:60.3.0-1.el6
Red Hat:enterprise_linux:6::clientfirefox-debuginfobefore 0:60.3.0-1.el60:60.3.0-1.el6
Red Hat:enterprise_linux:7::clientfirefoxbefore 0:60.3.0-1.el7_50:60.3.0-1.el7_5
Red Hat:enterprise_linux:7::clientfirefox-debuginfobefore 0:60.3.0-1.el7_50:60.3.0-1.el7_5
SUSE:Linux Enterprise Module for Desktop Applications 15MozillaFirefoxbefore 60.3.0-3.17.160.3.0-3.17.1
SUSE:OpenStack Cloud 7MozillaFirefoxbefore 60.3.0-109.50.260.3.0-109.50.2

Same product

mozilla: all records

Other highest-scoring records for the same primary product.

  • CVE-2010-3765Mozilla Firefox 3.5.x through 3.5.14 and 3.6.x through 3.6.11, Thunderbird 3.1.6 before 3.1.6 and 3.0.x before 3.0.10, and SeaMonkey 2.x befKEV
    94Now
  • CVE-2019-11708Insufficient vetting of parameters passed with the Prompt:Open IPC message between child and parent processes can result in the non-sandboxeKEV
    87Now
  • CVE-2015-4495The PDF reader in Mozilla Firefox before 39.0.3, Firefox ESR 38.x before 38.1.1, and Firefox OS before 2.2 allows remote attackers to bypassKEV
    86Now

Published before and after this one in the same product

  • ← EarlierCVE-2018-12392Feb 28, 2019 · When manipulating user events in nested loops while opening a document through script, it is possible to trigger a potentially exploitable c
    40Plan
  • ← EarlierCVE-2018-12393Feb 28, 2019 · A potential vulnerability was found in 32-bit builds where an integer overflow during the conversion of scripts to an internal UTF-16 repres
    31Monitor
  • Later →CVE-2018-12396Feb 28, 2019 · A vulnerability where a WebExtension can run content scripts in disallowed contexts following navigation or other events.
    27Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
debian:firefox-esr60.3.0esr-1 · Debian:12Package registry (OSV)
red hat:firefox0:60.3.0-1.el7_5 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:firefox-debuginfo0:60.3.0-1.el7_5 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
suse:MozillaFirefox60.3.0-3.17.1 · SUSE:Linux Enterprise Module for Desktop Applications 15Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
none
Availability
none
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
None
Availability impact
None

Weakness class (CWE)

—

CVSS vector

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

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (10 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records