Public Date:
833704: CVE-2012-3405 glibc: incorrect use of extend_alloca() in formatted printing can lead to FORTIFY_SOURCE format string protection bypass

The MITRE CVE dictionary describes this issue as:

The vfprintf function in stdio-common/vfprintf.c in libc in GNU C Library (aka glibc) 2.14 and other versions does not properly calculate a buffer length, which allows context-dependent attackers to bypass the FORTIFY_SOURCE format-string protection mechanism and cause a denial of service (segmentation fault and crash) via a format string with a large number of format specifiers that triggers "desynchronization within the buffer size handling," a different vulnerability than CVE-2012-3404.

Find out more about CVE-2012-3405 from the MITRE CVE dictionary dictionary and NIST NVD.


This issue did not affect the version of glibc as shipped with Red Hat Enterprise Linux 5.

CVSS v2 metrics

NOTE: The following CVSS v2 metrics and score provided are preliminary and subject to review.

Base Score 6.8
Base Metrics AV:N/AC:M/Au:N/C:P/I:P/A:P
Access Vector Network
Access Complexity Medium
Authentication None
Confidentiality Impact Partial
Integrity Impact Partial
Availability Impact Partial

Find out more about Red Hat support for the Common Vulnerability Scoring System (CVSS).

Red Hat Security Errata

Platform Errata Release Date
Red Hat Enterprise Linux version 6 (glibc) RHSA-2012:1098 2012-07-18
RHEV Hypervisor for RHEL-6 (rhev-hypervisor6) RHSA-2012:1200 2012-08-23

Affected Packages State

Platform Package State
Red Hat Enterprise Linux 5 glibc Not affected