dbcve.org
Debian LinuxOperating system · Debian

CVE-2016-9893

CRITICAL · 9.8 CVSS v3.0 Published 2018-06-11
Fix available
A fix is available. Upgrade to 45.6.0 / 50.1 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
Memory safety bugs were reported in Thunderbird 45.5. Some of these bugs showed evidence of memory corruption and we presume that with enough effort that some of these could be exploited to run arbitrary code. This vulnerability affects Firefox < 50.1, Firefox ESR < 45.6, and Thunderbird < 45.6.

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

Memory safety bugs in Thunderbird 45.5 and Firefox showed evidence of memory corruption. These use-after-free or similar memory corruption flaws could potentially be exploited to achieve arbitrary code execution with sufficient effort.

MitigationUpgrade to Firefox 50.1 or higher, Firefox ESR 45.6 or higher, or Thunderbird 45.6 or higher to patch the memory safety vulnerabilities.

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:= 9.0
Enterprise LinuxOperating system
Affected:= 5.0= 6.0= 7.0
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
FirefoxWeb browser
Affected:< 50.1< 45.6.0

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 Firefox version
    Run 'firefox --version' or go to Firefox menu > Help > About Firefox
    Affected if Version is less than 45.6.0 or between 45.6.0 and 50.0 (excluding 50.1)
  2. Check Thunderbird version
    Run 'thunderbird --version' or go to Thunderbird menu > Help > About Thunderbird
    Affected if Version is 45.5 or if the installed version is in the 45.x range below 45.6
  3. Verify Red Hat Enterprise Linux version
    Run 'cat /etc/redhat-release' or 'hostnamectl'
    Affected if The system runs RHEL 5.0, 6.0, 7.0, 7.3, 7.4, or 7.5 and has Firefox/Thunderbird installed from system packages
  4. Verify Debian Linux version
    Run 'cat /etc/debian_version'
    Affected if The system runs Debian 9.0 and has Firefox/Thunderbird installed from system packages
  5. Check for Firefox ESR version
    Run 'firefox --version' and check if it is an ESR release (Extended Support Release)
    Affected if Firefox ESR version is less than 45.6

A user is affected if they are running Firefox versions below 45.6.0 (non-ESR) or below 50.1, or Thunderbird 45.5, on any of the listed Red Hat or Debian Linux 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 45.6.0 / 50.1 or later
Fixed in 45.6.050.1
Interim mitigation

Upgrade to Firefox 50.1 or higher, Firefox ESR 45.6 or higher, or Thunderbird 45.6 or higher to patch the memory safety vulnerabilities.

Recommended fix High confidence

Firefox 50.1+, Firefox ESR 45.6+, or Thunderbird 45.6+

  1. Backup your profile data (bookmarks, passwords, emails) before upgrading
  2. For Debian Linux 9.0: Run 'apt-get update && apt-get upgrade' to receive security updates
  3. For RHEL/CentOS systems: Run 'yum update' or 'dnf update' to apply security patches
  4. For Firefox: Download and install Firefox 50.1 or later from mozilla.org
  5. For Firefox ESR: Upgrade to Firefox ESR 45.6 or later
  6. For Thunderbird: Upgrade to Thunderbird 45.6 or later
  7. Restart the application after upgrade
Caveat Upgrading may cause incompatibility with older extensions/add-ons; some legacy features or plugins may no longer work in newer versions

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

Fix this in Debian Linux Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA1.0 h
9.0 hours of engineering $1,600
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,560.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2016-9893 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2016-9893 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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