Vulnerability Note VU#681569

Linux Kernel may fail to properly handle SNMP packets

Overview

A memory freeing vulnerability in the Linux kernel module ip_nat_snmp_basic can be exploited to create a denial-of-service condition.

I. Description

ip_nat_snmp_basic

The ip_nat_snmp_basic IP NAT module is intended for use with SNMP network discovery and monitoring applications where target networks use conflicting private IP addresses .

snmp_trap_decode()

The snmp_trap_decode()function decodes v1 and v2 SNMP messages.

The Problem

The function snmp_trap_decode() in the Linux kernel module ip_nat_snmp_basic fails to properly free memory when handling certain SNMP packets.

II. Impact

A remote attacker could cause a system running Linux kernel version < 2.6.16.18 with the ip_nat_snmp_basic module loaded to crash. This results in a denial-of-service condition.

III. Solution

Apply an update

See the systems affected section of this document for information about specific vendors. Users who compile the Linux kernel from source are encouraged to upgrade to Linux kernel version 2.6.16.18.

Do not use ip_nat_snmp_basic

Do not load the ip_nat_snmp_basic kernel module if it is not needed.

Restrict Access

Limit access to SNMP ports (default 161/udp and 162/udp) to trusted hosts.

Systems Affected

Vendor	Status	Date Notified	Date Updated
Mandriva, Inc.	Vulnerable	9-Jun-2006
Trustix Secure Linux	Vulnerable	9-Jun-2006

References

http://secunia.com/advisories/20225/
http://kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.16.18
http://secunia.com/advisories/20182/

Credit

This vulnerability was reported by Patrick McHardy.

This document was written by Ryan Giobbi.

Other Information

Date Public:	2006-05-23
Date First Published:	2006-06-09
Date Last Updated:	2006-07-13
CERT Advisory:
CVE-ID(s):	CVE-2006-2444
NVD-ID(s):	CVE-2006-2444
US-CERT Technical Alerts:
Metric:	2.69
Document Revision:	21

If you have feedback, comments, or additional information about this vulnerability, please send us email.

Produced 2006 by US-CERT, a government organization
Disclaimers and copyright information

Get Adobe Reader