The vulnerable system is bound to a protocol stack, but the attack is limited at the protocol level to a logically adjacent topology. This can mean an attack must be launched from the same shared proximity (e.g., Bluetooth, NFC, or IEEE 802.11) or logical network (e.g., local IP subnet), or from within a secure or otherwise limited administrative domain (e.g., MPLS, secure VPN within an administrative network zone). One example of an Adjacent attack would be an ARP (IPv4) or neighbor discovery flood leading to a denial of service on the local LAN segment (e.g., CVE-2013-6014).
Attack Complexity
Low
AC
The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Privileges Required
None
PR
The attacker is unauthenticated prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction
None
UI
The vulnerable system can be exploited without interaction from any human user, other than the attacker. Examples include: a remote attacker is able to send packets to a target system a locally authenticated attacker executes code to elevate privileges
Scope
Unchanged
S
An exploited vulnerability can only affect resources managed by the same security authority. In the case of a vulnerability in a virtualized environment, an exploited vulnerability in one guest instance would not affect neighboring guest instances.
Confidentiality
High
C
There is total information disclosure, resulting in all data on the system being revealed to the attacker, or there is a possibility of the attacker gaining control over confidential data.
Integrity
High
I
There is a total compromise of system integrity. There is a complete loss of system protection, resulting in the attacker being able to modify any file on the target system.
Availability
High
A
There is a total shutdown of the affected resource. The attacker can deny access to the system or data, potentially causing significant loss to the organization.
Check Point Software Technologies - Vulnerability Discovery Team (VDT)
http://www.checkpoint.com/defense/
rpc.pcnfsd syslog format string vulnerability
CVE-2010-1039
INTRODUCTION
There exists a vulnerability within a log function of the rpc.pcnfsd service
which when properly exploited can lead to remote compromise of the vulnerable
system.
This vulnerability was confirmed in the following versions and operating
systems, other versions and operating systems may be also affected.
IBM AIX 6.1.0 and lower
IRIX 6.5
HP-UX 11.11, 11.23, 11.31
DETAILS
This vulnerability can be triggered by sending a rpc request resulting in an
invalid directory causing the service to call _msgout() function that call
syslog() function to log the error without checking for formatted strings.
This is the vulnerable function (pcnfsd version 1.2 source).
from pcnfsd_print.c
psrstat pr_start2(system, pr, user, fname, opts, id)
...
...
if (rename(pathname, new_pathname))
{
/*
**---------------------------------------------------------------
** Should never happen.
**---------------------------------------------------------------
*/
(void)sprintf(tempstr, "rpc.pcnfsd: spool file rename (%s->%s) failed.n",
pathname, new_pathname);
msg_out(tempstr); <---- Vuln Function with our input
form pcnfsd_xdr.c
static
_msgout(msg)
char *msg;
{
#ifdef RPC_SVC_FG
if (_rpcpmstart)
syslog(LOG_ERR, msg); <---- Problem here!
else
(void) fprintf(stderr, "%sn", msg);
#else
syslog(LOG_ERR, msg); <---- Problem here!
#endif
return(0);
}
GDB output:
Program received signal SIGSEGV, Segmentation fault.
0xd01e28cc in _doprnt () from /usr/lib/libc.a(shr.o)
(gdb) bt
#0 0xd01e28cc in _doprnt () from /usr/lib/libc.a(shr.o)
#1 0xd01dd4fc in vfprintf () from /usr/lib/libc.a(shr.o)
#2 0xd024be10 in __syslog_r () from /usr/lib/libc.a(shr.o)
#3 0xd024c400 in syslog () from /usr/lib/libc.a(shr.o)
#4 0x10000d98 in ?? ()
CREDITS
This vulnerability was discovered and exploited by Rodrigo Rubira Branco from Check Point Vulnerability Discovery Team (VDT).
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