Asterisk chan_sip Overlap Dialing Feature DoS (AST-2016-007)

high Nessus Plugin ID 93534

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Synopsis

A telephony application running on the remote host is affected by a denial of service vulnerability.

Description

According to its SIP banner, the version of Asterisk running on the remote host is 11.x prior to 11.23.1, 13.x prior to 13.11.1, 11.6-certx prior to 11.6-cert15, or 13.8-certx prior to 13.8-cert3. It is, therefore, affected by a flaw in the overlap dialing feature in chan_sip due to a failure to release old RTP resources before allocating new ones. An unauthenticated, remote attacker can exploit this to exhaust available RTP ports and stop new RTP sessions from being created, resulting in a denial of service condition. This vulnerability only affects installations using the overlap dialing support feature.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Upgrade to Asterisk version 11.23.1 / 13.11.1 / 11.6-cert15 / 13.8-cert3 or later. Alternatively, disable the overlap dialing support feature.

Plugin Details

Severity: High

ID: 93534

File Name: asterisk_ast_2016_007.nasl

Version: 1.10

Type: remote

Family: Misc.

Published: 9/15/2016

Updated: 4/11/2022

Configuration: Enable paranoid mode, Enable thorough checks

Supported Sensors: Nessus

Risk Information

CVSS v2

Risk Factor: Medium

Base Score: 5

Temporal Score: 3.7

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/a:digium:asterisk

Required KB Items: Settings/ParanoidReport, asterisk/sip_detected

Patch Publication Date: 9/8/2016

Vulnerability Publication Date: 9/8/2016

Reference Information

BID: 92888

Detections

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