Gentoo Logo

net-snmp: Authorization bypass


1.  Gentoo Linux Security Advisory

Version Information

Advisory Reference GLSA 201001-05 / net-snmp
Release Date January 13, 2010
Latest Revision January 13, 2010: 01
Impact normal
Exploitable remote
Package Vulnerable versions Unaffected versions Architecture(s)
net-analyzer/net-snmp < >= All supported architectures

Related bugreports: #250429


A remote attacker can bypass the tcp-wrappers client authorization in net-snmp.

2.  Impact Information


net-snmp bundles software for generating and retrieving SNMP data.


The netsnmp_udp_fmtaddr() function (snmplib/snmpUDPDomain.c), when using TCP wrappers for client authorization, does not properly parse hosts.allow rules.


A remote, unauthenticated attacker could bypass the ACL filtering, possibly resulting in the execution of arbitrary SNMP queries.

3.  Resolution Information


If possible, protect net-snmp with custom iptables rules:

Code Listing 3.1: Workaround

iptables -s [client] -d [host] -p udp --dport 161 -j ACCEPT
iptables -s -d [host] -p udp --dport 161 -j DROP


All net-snmp users should upgrade to the latest version:

Code Listing 3.2: Resolution

# emerge --sync
# emerge --ask --oneshot --verbose ">=net-analyzer/net-snmp-"

4.  References


Page updated January 13, 2010

Summary: This is a Gentoo Linux Security Advisory

Security Team
Contact Address

Donate to support our development efforts.

Copyright 2001-2015 Gentoo Foundation, Inc. Questions, Comments? Contact us.