Debian LinuxOperating system · Debian
CVE-2018-8048
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 · uneditedIn the Loofah gem through 2.2.0 for Ruby, non-whitelisted HTML attributes may occur in sanitized output by republishing a crafted HTML fragment.
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 · moderate confidenceThe Loofah gem (Ruby HTML/XML sanitizer) versions through 2.2.0 contains a flaw where non-whitelisted HTML attributes can appear in sanitized output when a crafted HTML fragment is 'republished' - meaning the sanitized content is processed or serialized again, allowing attribute allowlists to be bypassed.
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
= 9.0
LoofahApplication
< 2.2.1CVSS 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
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
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.
-
Check installed Loofah gem versionRun 'gem list loofah' or inspect your Gemfile.lock for the loofah version entryAffected if Version is below 2.2.1 (e.g., 2.2.0 or earlier)
-
Identify Loofah usage in codebaseSearch for 'require "loofah"' or 'require "loofah/fragment"' in your Ruby source files to locate where Loofah is loadedAffected if Loofah is used in your application
-
Detect reprocessing of sanitized contentSearch for patterns where Loofah sanitized output is fed back into Loofah for processing a second time (e.g., Loofah.scrub(string) being called on output that was already sanitized, or storing sanitized content and re-parsing it later)Affected if Your code takes previously sanitized HTML and sanitizes it again (republishes)
-
Check for custom attribute allowlistsInspect Loofah calls for custom scrubber configurations (e.g., :attributes => [...] options) to see if any unsafe attribute configurations are in useAffected if Custom attribute allowlists are defined and content is reprocessed
-
Check Debian system package version (if using system Ruby)Run 'dpkg -l | grep loofah' or check if loofah gem came from Debian packagesAffected if Running Debian 9.0 with loofah package version below 2.2.1
You are affected if Loofah version is below 2.2.1 AND your application reprocesses previously sanitized HTML content through Loofah, allowing attribute allowlists to be bypassed.
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 data2.2.1
Update the Loofah gem to a version newer than 2.2.0. Review existing code that uses Loofah to ensure sanitized content is not being reprocessed in ways that could trigger the bypass.
Fix this in Debian Linux
Scoped from the published advisory
- Consultation2.0 h
- Implementation1.0 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 $1,696.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2018-8048 — 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-2018-8048 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
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.
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.
- 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