Vigil@nce - AIX: privilege escalation via Malloc
July 2014 by Vigil@nce
This bulletin was written by Vigil@nce : http://vigilance.fr/offer
SYNTHESIS OF THE VULNERABILITY
A local attacker can force a suid/sgid application on AIX to
create a file with a privileged user/group, in order to escalate
his privileges.
Impacted products: AIX
Severity: 2/4
Creation date: 01/07/2014
DESCRIPTION OF THE VULNERABILITY
Functions of the Malloc family are used by programs to allocate
memory.
The MALLOCOPTIONS and MALLOCBUCKETS environment variables alter
the behavior of Malloc functions. The "bucket_statistics:path"
option indicates the path of the file where to write statistics on
Buckets (frequent allocation of small areas).
Suid/sgid programs use Malloc functions. However, the library does
not drop its privileges, before creating the statistic file.
A local attacker can therefore force a suid/sgid application on
AIX to create a file with a privileged user/group, in order to
escalate his privileges.
ACCESS TO THE COMPLETE VIGIL@NCE BULLETIN
http://vigilance.fr/vulnerability/AIX-privilege-escalation-via-Malloc-14956