Permissions, Privileges, and Access Controls in Glibc

1) Permissions, Privileges, and Access Controls

EUVDB-ID: #VU110114

Risk: Medium

CVSSv4.0: 2.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2012-3406

CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls

Exploit availability: No

Description

The vulnerability allows a remote non-authenticated attacker to read and manipulate data.

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.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Glibc: All versions

CPE2.3

• cpe:2.3:a:gnu:glibc:*:*:*:*:*:*:*:*

External links

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

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.