Leak of SNMP write password via SNMP read community in NETGEAR WG102 - Prosafe 802.11g Access Point

Dear all,

    after informing Netgear about the unsafe handling of passwords on their WG102 Access Points

nothing happened for several weeks. To inform other users about the potential threat to their
networks I decided to share my findings.

WG102 offers the the typical SNMP write & SNMP read community password 'protection'. SNMPv2 is
already known for weak security, yet NETGEAR goes one step further:

the SNMP write community (password) is accessible in cleartext via the MIB which is readable via the
SNMP read community.

Affected Versions:

• Netgear WG102
  - with Firmware 4.0.16
  - Firmware 4.0.27 (latest as of 2009-01-09)

• other firmwares and similar products probably have the same bug (just an assumption!)

Possible consequences:

• leakage of admin/write password

• Once an attacker has SNMP write acccess, she can freely reconfigure the access point. Including
  e.g. redirect RADIUS authentication to a rogue server.

To reproduce:

enable snmp (default) and set different SNMP write/read passwords.

then on a different machine do:

snmpwalk -c READPASSWORD -v2c IP SNMPv2-SMI::enterprises.4526.4.3

the passwords are stored in …4526.4.3.8.4.0 and …4526.4.3.8.5.0

Proposed fixes:

do not enable SNMP at all. vendor fix required.

Best Regards

'Harm S.I. Vaittes'