1.4.6 Do not Configure a Read Write SNMP Community String

Information

SNMP RW (Read-Write) access allows stations with Management access to both read and write SNMP MIB objects.

Rationale:

SNMP is typically used for monitoring specific operational characteristics of the switch. These tasks typically only require read access. Permitting RW (Read-Write) access permits SNMP to modify some SNMP values.

Impact:

Permitting SNMP RW Access not only allows 'write' access to some SNMP MIB Objects, which allows a malicious attacker to modify some operational characterstics of the switch. By extension this access allows a malicious actor to collect the entire configuration of the device.

Solution

Only use RO groups for SNMPv2. The most common implementation is 'network-operator', because if you use the legacy syntax:

switch(config)# snmp-server community <some complex string> ro

the switch will translate this to the new syntax, using 'network-operator' group

switch(config)# snmp-server community <some complex string> group network-operator

Default Value:

SNMP is not configured by default. The default SNMP Groups and permissions are:

switch# sho snmp group



Role: aaa-db-admin

Description: Predefined AAA DB admin, has no cli permissions. Allows RESTful A

PI

-------------------------------------------------------------------

Rule Perm Type Scope Entity

-------------------------------------------------------------------

1 permit read-write



Role: aaa-db-operator

Description: Predefined AAA DB operator, has no cli permissions. Allows RESTfu

l API

-------------------------------------------------------------------

Rule Perm Type Scope Entity

-------------------------------------------------------------------

1 permit read



Role: l3-db-admin

Description: Predefined L3 DB admin, has no cli permissions. Allows RESTful AP

I

-------------------------------------------------------------------

Rule Perm Type Scope Entity

-------------------------------------------------------------------

1 permit read-write



Role: l3-db-operator

Description: Predefined L3 DB operator, has no cli permissions. Allows RESTful

API

-------------------------------------------------------------------

Rule Perm Type Scope Entity

-------------------------------------------------------------------

1 permit read



Role: network-admin

Description: Predefined network admin role has access to all commands

on the switch

-------------------------------------------------------------------

Rule Perm Type Scope Entity

-------------------------------------------------------------------

1 permit read-write



Role: network-operator

Description: Predefined network operator role has access to all read

commands on the switch

-------------------------------------------------------------------

Rule Perm Type Scope Entity

-------------------------------------------------------------------

1 permit read



Role: nxdb-admin

Description: Predefined nxdb-admin role has no cli permissions.

Allows json-rpc get and set.

-------------------------------------------------------------------

Rule Perm Type Scope Entity

-------------------------------------------------------------------

1 deny command



Role: nxdb-operator

Description: Predefined nxdb-operator role has no cli permissions.

Allows json-rpc get.

-------------------------------------------------------------------

Rule Perm Type Scope Entity

-------------------------------------------------------------------

1 deny command



Role: vdc-admin

Description: Predefined vdc admin role has access to all commands within

a VDC instance

-------------------------------------------------------------------

Rule Perm Type Scope Entity

-------------------------------------------------------------------

1 permit read-write



Role: vdc-operator

Description: Predefined vdc operator role has access to all read commands

within a VDC instance

-------------------------------------------------------------------

Rule Perm Type Scope Entity

-------------------------------------------------------------------

1 permit read



Role: dev-ops

Description: Predefined system role for devops access. This role

cannot be modified.

-------------------------------------------------------------------

Rule Perm Type Scope Entity

-------------------------------------------------------------------

6 permit command conf t ; username *

5 permit command attach module *

4 permit command slot *

3 permit command bcm module *

2 permit command run bash *

1 permit command python *



Role: priv-15

Description: This is a system defined privilege role.

Vlan policy: permit (default)

Interface policy: permit (default)

Vrf policy: permit (default)

-------------------------------------------------------------------

Rule Perm Type Scope Entity

-------------------------------------------------------------------

1 permit read-write



Role: priv-14

Description: This is a system defined privilege role.

Vlan policy: permit (default)

Interface policy: permit (default)

Vrf policy: permit (default)

-------------------------------------------------------------------

Rule Perm Type Scope Entity

-------------------------------------------------------------------

1 permit read-write



Role: priv-13

Description: This is a system defined privilege role.

Vlan policy: permit (default)

Interface policy: permit (default)

Vrf policy: permit (default)



Role: priv-12

Description: This is a system defined privilege role.

Vlan policy: permit (default)

Interface policy: permit (default)

Vrf policy: permit (default)



Role: priv-11

Description: This is a system defined privilege role.

Vlan policy: permit (default)

Interface policy: permit (default)

Vrf policy: permit (default)



Role: priv-10

Description: This is a system defined privilege role.

Vlan policy: permit (default)

Interface policy: permit (default)

Vrf policy: permit (default)



Role: priv-9

Description: This is a system defined privilege role.

Vlan policy: permit (default)

Interface policy: permit (default)

Vrf policy: permit (default)



Role: priv-8

Description: This is a system defined privilege role.

Vlan policy: permit (default)

Interface policy: permit (default)

Vrf policy: permit (default)



Role: priv-7

Description: This is a system defined privilege role.

Vlan policy: permit (default)

Interface policy: permit (default)

Vrf policy: permit (default)



Role: priv-6

Description: This is a system defined privilege role.

Vlan policy: permit (default)

Interface policy: permit (default)

Vrf policy: permit (default)



Role: priv-5

Description: This is a system defined privilege role.

Vlan policy: permit (default)

Interface policy: permit (default)

Vrf policy: permit (default)



Role: priv-4

Description: This is a system defined privilege role.

Vlan policy: permit (default)

Interface policy: permit (default)

Vrf policy: permit (default)



Role: priv-3

Description: This is a system defined privilege role.

Vlan policy: permit (default)

Interface policy: permit (default)

Vrf policy: permit (default)



Role: priv-2

Description: This is a system defined privilege role.

Vlan policy: permit (default)

Interface policy: permit (default)

Vrf policy: permit (default)



Role: priv-1

Description: This is a system defined privilege role.

Vlan policy: permit (default)

Interface policy: permit (default)

Vrf policy: permit (default)



Role: priv-0

Description: This is a system defined privilege role.

Vlan policy: permit (default)

Interface policy: permit (default)

Vrf policy: permit (default)

-------------------------------------------------------------------

Rule Perm Type Scope Entity

-------------------------------------------------------------------

10 permit command traceroute6 *

9 permit command traceroute *

8 permit command telnet6 *

7 permit command telnet *

6 permit command ping6 *

5 permit command ping *

4 permit command ssh6 *

3 permit command ssh *

2 permit command enable *

1 permit read

See Also

https://workbench.cisecurity.org/files/3102

Item Details

Category: SYSTEM AND INFORMATION INTEGRITY

References: 800-53|SI-4, CSCv7|9.2

Plugin: Cisco

Control ID: 3901f216de2136a6ff2e4c51ae812e593067011203ac284a4dee673b4bda1f1e