dbcve.org
Enterprise Linux DesktopOperating system · Redhat

CVE-2017-5400

CRITICAL · 9.8 CVSS v3.0 Published 2018-06-11
Fix available
A fix is available. Upgrade to 45.8.0 / 52.0 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
JIT-spray targeting asm.js combined with a heap spray allows for a bypass of ASLR and DEP protections leading to potential memory corruption attacks. This vulnerability affects Firefox < 52, Firefox ESR < 45.8, Thunderbird < 52, and Thunderbird < 45.8.

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

JIT-spray attacks targeting asm.js combined with heap spray techniques bypass ASLR and DEP memory protections, enabling memory corruption and potential arbitrary code execution in affected Mozilla products.

MitigationUpgrade to Firefox 52+, Firefox ESR 45.8+, Thunderbird 52+, or Thunderbird ESR 45.8+ to patch this vulnerability.

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:= 5.0= 6.0= 7.0
Enterprise Linux ServerOperating system
Affected:= 5.0= 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:= 5.0= 6.0= 7.0
Debian LinuxOperating system
Affected:= 8.0
FirefoxWeb browser
Affected:< 45.8.0< 52.0
ThunderbirdApplication
Affected:< 45.8.0

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 if Firefox is installed
    Run 'firefox --version' or check for Firefox in /usr/bin/firefox or look for the firefox package using your system package manager (rpm -q firefox or dpkg -l firefox)
    Affected if Firefox is installed and its version is below 52.0 (with critical risk at versions below 45.8.0)
  2. Check if Thunderbird is installed
    Run 'thunderbird --version' or check for Thunderbird in /usr/bin/thunderbird or look for the thunderbird package using your system package manager (rpm -q thunderbird or dpkg -l thunderbird)
    Affected if Thunderbird is installed and its version is below 45.8.0
  3. Determine exact Firefox version
    Run 'firefox --version' to get the precise version number, or check the package details with 'rpm -qi firefox' or 'dpkg -s firefox'
    Affected if Version shown is less than 45.8.0 (definitely affected) or between 45.8.0 and 52.0 (affected per vendor scope)
  4. Determine exact Thunderbird version
    Run 'thunderbird --version' to get the precise version number, or check the package details with 'rpm -qi thunderbird' or 'dpkg -s thunderbird'
    Affected if Version shown is less than 45.8.0

You are affected if Firefox version is below 52.0 (especially below 45.8.0) or Thunderbird version is below 45.8.0, as the JIT-spray vulnerability exists in these unpatched Mozilla product versions.

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 45.8.0 / 52.0 or later
Fixed in 45.8.052.0
Interim mitigation

Upgrade to Firefox 52+, Firefox ESR 45.8+, Thunderbird 52+, or Thunderbird ESR 45.8+ to patch this vulnerability.

Recommended fix High confidence

Firefox 52.0 (or Firefox ESR 45.8); Thunderbird 52.0 (or Thunderbird ESR 45.8)

  1. For Firefox users: Upgrade to Firefox 52.0 or later (or Firefox ESR 45.8 or later for extended support)
  2. For Thunderbird users: Upgrade to Thunderbird 52.0 or later (or Thunderbird ESR 45.8 or later)
  3. On RHEL/CentOS systems: Run 'yum update firefox' or 'yum update thunderbird' to apply vendor security updates
  4. On Debian/Ubuntu systems: Run 'apt-get update && apt-get install firefox' or 'apt-get update && apt-get install thunderbird'
  5. Restart the browser/application after updating to ensure the patched version is loaded
  6. Verify the installed version by checking Help > About Firefox or About Thunderbird

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

Fix this in Enterprise Linux Desktop Scoped from the published advisory
  • Consultation2.0 h
  • Implementation3.0 h
  • Testing2.0 h
  • Review / QA1.0 h
8.0 hours of engineering $1,420
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,272.

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-2017-5400 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