Ubuntu LinuxOperating system · Canonical
CVE-2018-5177
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 · uneditedA vulnerability exists in XSLT during number formatting where a negative buffer size may be allocated in some instances, leading to a buffer overflow and crash if it occurs. This vulnerability affects Firefox < 60.
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 confidenceA buffer overflow vulnerability exists in Firefox's XSLT (Extensible Stylesheet Language Transformations) processor during number formatting. The issue occurs when a negative buffer size is allocated due to an integer handling error, which leads to buffer overflow and subsequent crash. The flaw is triggered during XSLT transformations that involve number formatting operations.
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
Ubuntu LinuxOperating system
= 14.04= 16.04= 17.10= 18.04
FirefoxWeb browser
< 60.0CVSS 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
- None
- Integrity
- None
- Availability
- High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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 checksWork through these to decide whether this CVE applies to you.
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Check installed Firefox versionOpen Firefox, navigate to Help > About Firefox, or run 'firefox --version' from command line. Compare the version number to the affected range (versions below 60.0).Affected if Firefox version is below 60.0 (e.g., 59.x, 58.x, etc.)
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Verify XSLT processing usageInspect any web applications or documents that perform XSLT transformations, particularly those using xsl:number or format-number() functions. Check browser console for XSLT-related errors during page loads.Affected if The environment processes XSLT stylesheets with number formatting operations
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Check for automatic update statusIn Firefox, go to Options > Privacy & Security > Firefox Updates and verify whether updates are enabled or the browser is manually managed.Affected if Firefox updates are disabled or the browser is managed outside standard update channels
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Identify Ubuntu package version (if Firefox installed via apt)Run 'dpkg -l firefox' or 'apt-cache policy firefox' in terminal to confirm the installed package version.Affected if The Firefox package version is older than 60.0
You are affected if Firefox version is below 60.0 and your environment processes XSLT transformations with number formatting operations.
Generated from the published advisory. Verify against your own configuration.
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 data60.0
Upgrade Firefox to version 60 or later to receive the vendor patch. Organizations should ensure automatic updates are enabled or deploy the patched version through their software distribution mechanisms.
Fix this in Ubuntu Linux
Scoped from the published advisory
- Consultation2.0 h
- Implementation4.0 h
- Testing2.0 h
- Review / QA1.0 h
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 locallyCheck whether your project pulls in CVE-2018-5177 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2018-5177 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- 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
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