Configuring Sip Message Policy Rules - AudioCodes Mediant 800B User Manual

User's Manual
Parameter
Action Value
CLI: action-value
[MessageManipulations_Act
ionValue]
Row Role
CLI: row-role
[MessageManipulations_Ro
wRole]
18.5

Configuring SIP Message Policy Rules

The Message Policy table lets you configure up to 20 SIP Message Policy rules. SIP
Message Policy rules are used to block (blacklist) unwanted incoming SIP messages or
permit (whitelist) receipt of desired SIP messages. You can configure legal and illegal
characteristics of a SIP message. This feature is helpful against VoIP fuzzing (also known
as robustness testing), which sends different types of packets to its "victims" for finding
bugs and vulnerabilities. For example, the attacker might try sending a SIP message
containing either an oversized parameter or too many occurrences of a parameter.
To apply SIP Message Policy rules, you need to assign them to SIP Interfaces associated
with the relevant IP Groups (see ''Configuring SIP Interfaces'' on page 244).
Each Message Policy rule can be configured with the following:

Maximum message length

Maximum header length

Maximum message body length

Maximum number of headers

Maximum number of bodies

Option to send 400 "Bad Request" response if message request is rejected

Blacklist and whitelist for defined methods (e.g., INVITE)

Blacklist and whitelist for defined bodies
Version 6.8
before forwarding the message.
Defines a value that you want to use in the manipulation.
The default value is a string (case-insensitive) in the following
syntax:

string/<message-element>/<call-param> +

string/<message-element>/<call-param>
For example:

'itsp.com'

header.from.url.user

param.call.dst.user

param.call.dst.host + '.com'

param.call.src.user + '<' + header.from.url.user + '@' + header.p-
asserted-id.url.host + '>'
Note: Only single quotation marks must be used.
Determines which condition must be used for the rule of this table
row.

[0] Use Current Condition = The condition entered in this row
must be matched in order to perform the defined action (default).

[1] Use Previous Condition = The condition of the rule configured
directly above this row must be used in order to perform the
defined action. This option allows you to configure multiple
actions for the same condition.
Note: When multiple manipulations rules apply to the same header,
the next rule applies to the result string of the previous rule.
277
Description
Mediant 800B Gateway and E-SBC
18. SIP Definitions