Debian LinuxOperating system · Debian
CVE-2017-8312
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 · uneditedHeap out-of-bound read in ParseJSS in VideoLAN VLC due to missing check of string length allows attackers to read heap uninitialized data via a crafted subtitles file.
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 heap out-of-bounds read vulnerability exists in VLC's ParseJSS function used for parsing JSS subtitle files. The function fails to validate string lengths before reading, allowing an attacker to read uninitialized heap data by providing a crafted subtitles file with overly long string fields.
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
= 8.0< 2.2.6CVSS 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
- Local
- Complexity
- Low
- Privileges
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/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.
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Check if VLC is installedRun 'dpkg -l | grep vlc' on Debian or check for VLC binary with 'which vlc' or 'vlc --version'Affected if No VLC package is found or the command returns nothing, meaning VLC is not installed and this CVE does not apply
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Determine installed VLC versionRun 'vlc --version' or 'dpkg -l | grep vlc' to retrieve the exact version numberAffected if The version number is lower than 2.2.6 (e.g., 2.2.5, 2.2.4, 2.1.x, etc.) indicating the vulnerable version is installed
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Check if subtitle parsing is enabledAttempt to open a JSS subtitle file in VLC or verify subtitle codec support is loaded by checking VLC's codec information with 'vlc --list' or inspecting installed codec modulesAffected if Subtitle parsing modules are loaded and JSS format support is present, making the ParseJSS function reachable when opening JSS files
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Identify JSS subtitle file handlerCheck for libjss.so or similar JSS parser module in VLC's modules directory (typically /usr/lib/vlc/plugins/codec/ or within the application bundle)Affected if The JSS subtitle parser plugin exists in the VLC installation, confirming the vulnerable code path can be triggered
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Verify subtitle file access is possibleCheck if VLC can be used to load external subtitle files - this is typically enabled by default but can be confirmed by attempting to open any .jss file or checking preferencesAffected if VLC is configured to load external subtitle files, allowing a crafted JSS file to trigger the ParseJSS vulnerability
You are affected if VLC Media Player version is below 2.2.6 and the JSS subtitle parser module is present and enabled, allowing untrusted JSS subtitle files to trigger the heap out-of-bounds read.
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 data2.2.6
Update VLC to a version that includes the fix for CVE-2017-8312. Avoid opening untrusted JSS subtitle files with VLC until the patch is applied. Implement input validation on subtitle parsers.
Fix this in Debian Linux
Scoped from the published advisory
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,088.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2017-8312 — 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-2017-8312 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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- Version or environment caveats, and links to real fixes
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