The cap_bprm_set_creds function in security/commoncap.c in the Linux kernel before 3.3.3 does not properly handle the use of file system capabilities (aka fcaps) for implementing a privileged executable file, which allows local users to bypass intended personality restrictions via a crafted application, as demonstrated by an attack that uses a parent process to disable ASLR.

References

• https://nvd.nist.gov/vuln/detail/CVE-2012-2123
• torvalds/linux@d52fc5d
• https://bugzilla.redhat.com/show_bug.cgi?id=806722
• https://exchange.xforce.ibmcloud.com/vulnerabilities/75043
• http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=d52fc5dde171f030170a6cb78034d166b13c9445
• http://rhn.redhat.com/errata/RHSA-2012-0670.html
• http://rhn.redhat.com/errata/RHSA-2012-0743.html
• http://www.debian.org/security/2012/dsa-2469
• http://www.kernel.org/pub/linux/kernel/v3.x/ChangeLog-3.3.3
• http://www.openwall.com/lists/oss-security/2012/04/20/6
• http://www.securityfocus.com/bid/53166
• http://www.securitytracker.com/id?1027072
• http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=d52fc5dde171f030170a6cb78034d166b13c9445