dbcve.org
Enterprise VirtualizationApplication · Redhat

CVE-2012-3406

MEDIUM · 6.8 CVSS v2.0 Published 2014-02-10
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
77/100
Remediation priority · High
Remotely reachable No privileges Zero-click

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 · unedited
The vfprintf function in stdio-common/vfprintf.c in GNU C Library (aka glibc) 2.5, 2.12, and probably other versions does not "properly restrict the use of" the alloca function when allocating the SPECS array, which allows context-dependent attackers to bypass the FORTIFY_SOURCE format-string protection mechanism and cause a denial of service (crash) or possibly execute arbitrary code via a crafted format string using positional parameters and a large number of format specifiers, a different vulnerability than CVE-2012-3404 and CVE-2012-3405.

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 confidence

The vfprintf function in glibc's stdio-common/vfprintf.c improperly restricts the alloca function when allocating the SPECS array, allowing attackers to bypass FORTIFY_SOURCE format-string protection. Crafted format strings using positional parameters with a large number of format specifiers can cause a denial of service (crash) or potentially execute arbitrary code.

MitigationUpgrade the glibc library to a version with the CVE-2012-3406 fix applied. Prioritize patching systems that process user-controlled format strings through vfprintf-based functions.

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
Enterprise VirtualizationApplication
Affected:= 3.0
Ubuntu LinuxOperating system
Affected:= 8.04= 10.04= 11.04= 11.10= 12.04
Enterprise LinuxOperating system
Affected:= 5= 6.0
GlibcFramework / library
Affected:= 2.5= 2.12

CVSS 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
M
Authentication
None
Confidentiality
Partial
Integrity
Partial
Availability
Partial

AV:N/AC:M/Au:N/C:P/I:P/A:P

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 checks

Work through these to decide whether this CVE applies to you.

  1. Identify glibc version
    Run 'ldd --version' or 'rpm -q glibc' (RHEL) or 'dpkg -l libc6' (Ubuntu) to determine the installed glibc version
    Affected if The installed version is 2.5, 2.12, or falls within the affected RHEL 5-6.0 or Ubuntu 8.04-12.04 ranges listed in the CVE
  2. Check for format string usage in applications
    Audit applications for code that passes user-supplied strings to printf-family functions (printf, sprintf, fprintf, vfprintf) without format specifiers, or use static analysis tools to identify potential format string vulnerabilities
    Affected if Applications process user-controlled format strings through vfprintf-based functions
  3. Identify vfprintf call paths
    Review code that calls vfprintf or related stdio-common functions with format strings that could contain positional parameters (%n$s style)
    Affected if Code paths exist where untrusted input can reach vfprintf with crafted positional format specifiers
  4. Verify FORTIFY_SOURCE status
    Check if compiled binaries have FORTIFY_SOURCE enabled by running 'readelf -s binary | grep _chk' or examining compilation flags in build logs
    Affected if FORTIFY_SOURCE is not enabled or can be bypassed by the vulnerability

A system is affected if it runs a vulnerable glibc version (2.5, 2.12, or the listed RHEL/Ubuntu versions) AND processes user-controlled format strings through vfprintf-based functions with positional parameters.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade the glibc library to a version with the CVE-2012-3406 fix applied. Prioritize patching systems that process user-controlled format strings through vfprintf-based functions.

Fix this in Enterprise Virtualization Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing12.0 h
  • Review / QA4.0 h
28.0 hours of engineering $4,760
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $7,616.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2012-3406 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2012-3406 in production — separate from our analysis above.

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.

What this is

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.

What belongs here
  • 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