CVE-2008-3196
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 · uneditedskeleton.c in yacc does not properly handle reduction of a rule with an empty right hand side, which allows context-dependent attackers to cause an out-of-bounds stack access when the yacc stack pointer points to the end of the stack.
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 vulnerability exists in skeleton.c, the code generation template used by yacc to produce parsers. When yacc reduces a grammar rule with an empty right-hand side (epsilon production), it fails to properly validate stack bounds before accessing the parser stack. If the stack pointer is at the stack's end, this causes an out-of-bounds memory access, leading to potential denial of service or undefined behavior.
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 dataall versionsCVSS 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
- Authentication
- None
- Confidentiality
- None
- Integrity
- None
- Availability
- Complete
AV:N/AC:L/Au:N/C:N/I:N/A:C
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 if your application uses a yacc-generated parserSearch source code for the presence of yyparse(), yylex(), or yacc-related header files (y.tab.h, y.tab.c) or look for comment markers typically added by yacc generationAffected if The application contains a parser generated by yacc (look for functions like yyparse, yylex, or files named y.tab.c or similar)
-
Locate the yacc skeleton file used during parser generationCheck for skeleton.c in the yacc installation directory or look for references to skeleton files in build documentation; if you built yacc from source, examine the skeleton.c file in the source treeAffected if The skeleton.c file is the original unmodified version from an unpatched yacc distribution
-
Verify if the grammar contains epsilon productionsExamine the yacc grammar file (.y file) for rules with empty right-hand side (rules that simply produce nothing, often shown as 'rule : /* empty */' or 'rule : ;')Affected if The grammar includes one or more epsilon (empty) productions
-
Check the generated parser for stack bounds validationExamine the generated parser source code (y.tab.c) around the reduce action for epsilon productions; look for code that accesses yyvs[-1] or similar stack indices without prior bounds checkingAffected if The generated parser code performs stack access in reduce actions for epsilon productions without proper stack pointer validation
You are affected if your application uses a parser generated by yacc containing epsilon productions, built with an unpatched version of yacc whose skeleton.c lacks stack bounds validation before accessing the parser stack during epsilon production reduction.
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 dataUsers should rebuild their yacc-generated parsers using a patched version of yacc that corrects the stack management in skeleton.c. If no patched yacc is available, consider migrating to alternative parser generators like bison with equivalent functionality.
- 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-2008-3196 — 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-2008-3196 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