Vigil@nce: AIX, file creation via _LIB_INIT_DBG
August 2009 by Vigil@nce
A local attacker can use _LIB_INIT_DBG and a suid root program, in
order to create a file owned by root.
Severity: 1/4
Consequences: data creation/edition
Provenance: user shell
Means of attack: no proof of concept, no attack
Ability of attacker: expert (4/4)
Confidence: confirmed by the editor (5/5)
Diffusion of the vulnerable configuration: high (3/3)
Creation date: 05/08/2009
IMPACTED PRODUCTS
– IBM AIX
DESCRIPTION OF THE VULNERABILITY
The _LIB_INIT_DBG and _LIB_INIT_DBG_FILE environment variables are
used to debug applications linked to libc.a or libC.a. Debugging
information is stored in the file indicated by _LIB_INIT_DBG_FILE.
However, if a suid root program is debugged, the debug file is
created with root privileges (instead to loosing privileges to
those of the current user).
A local attacker can therefore use _LIB_INIT_DBG and a suid root
program, in order to create a file owned by root.
CHARACTERISTICS
Identifiers: BID-35934, VIGILANCE-VUL-8917
http://vigilance.fr/vulnerability/AIX-file-creation-via-LIB-INIT-DBG-8917