Debian LinuxOperating system · Debian
CVE-2017-5448
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 · uneditedAn out-of-bounds write in "ClearKeyDecryptor" while decrypting some Clearkey-encrypted media content. The "ClearKeyDecryptor" code runs within the Gecko Media Plugin (GMP) sandbox. If a second mechanism is found to escape the sandbox, this vulnerability allows for the writing of arbitrary data within memory, resulting in a potentially exploitable crash. This vulnerability affects Firefox ESR < 45.9, Firefox ESR < 52.1, and Firefox < 53.
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 confidenceAn out-of-bounds write vulnerability exists in Firefox's ClearKeyDecryptor component when processing Clearkey-encrypted media content. The flaw allows writing arbitrary data to memory at an arbitrary location, which can cause a potentially exploitable crash. The vulnerable code runs within the Gecko Media Plugin (GMP) sandbox, requiring a separate sandbox escape mechanism for full remote code execution.
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
= 7.0
Enterprise LinuxOperating system
= 6.0= 7.0
Enterprise Linux DesktopOperating system
= 6.0= 7.0
Enterprise Linux ServerOperating system
= 6.0= 7.0
Enterprise Linux Server AusOperating system
= 7.3= 7.4
Enterprise Linux Server EusOperating system
= 7.3= 7.4= 7.5
Enterprise Linux WorkstationOperating system
= 6.0= 7.0
FirefoxWeb browser
< 45.9.0>= 52.0, < 52.1.0< 53.0CVSS 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
- Low
- Integrity
- Low
- Availability
- High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/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.
-
Identify Firefox versionOpen Firefox, click the menu button, select Help, then About Firefox. Alternatively, visit about:support or run `firefox --version` from command line.Affected if Version is less than 45.9.0, OR between 52.0 and 52.1.0 (exclusive), OR less than 53.0
-
Confirm ClearKey or EME is enabledIn Firefox, type about:config in the address bar, then search for 'mediasource' or 'clearkey' settings. Look for preference names related to Encrypted Media Extensions or ClearKey DRM functionality.Affected if Any ClearKey/EME-related media preference is set to true, indicating the vulnerable code path can be triggered
-
Verify GMP sandbox statusVisit about:support and check the Gecko Media Plugin section, or look for GMP-related entries in about:plugins.Affected if GMP plugins are enabled, as the vulnerable ClearKeyDecryptor code runs within the GMP sandbox
You are affected if Firefox version falls within the vulnerable ranges (<45.9.0, >=52.0 to <52.1.0, or <53.0) AND ClearKey/EME media features are enabled in the browser.
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 data45.9.052.1.053.0
Upgrade Firefox to version 45.9 or higher for ESR 45 users, 52.1 or higher for ESR 52 users, or version 53 or higher for standard Firefox users.
Fix this in Debian Linux
Scoped from the published advisory
- Consultation1.0 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 $1,376.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2017-5448 — 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-2017-5448 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