Executive Summary

Summary
Title Cisco ASA and FTD SIP Inspection denial-of-service vulnerability
Informations
NameVU#339704First vendor Publication2018-11-01
VendorVU-CERTLast vendor Modification2018-11-05
Severity (Vendor) N/ARevisionM

Security-Database Scoring CVSS v2

Cvss vector :
Cvss Base ScoreN/AAttack RangeN/A
Cvss Impact ScoreN/AAttack ComplexityN/A
Cvss Expoit ScoreN/AAuthenticationN/A
Calculate full CVSS 2.0 Vectors scores

Detail

Vulnerability Note VU#339704

Cisco ASA and FTD SIP Inspection denial-of-service vulnerability

Original Release date: 01 Nov 2018 | Last revised: 05 Nov 2018

Overview

Cisco Adaptive Security Appliance (ASA) software and Cisco Firepower Threat Defense (FTD) software fails to properly parse SIP traffic, which can result in a denial-of-service condition on affected devices.

Description

Cisco Adaptive Security Appliance (ASA) software and Cisco Firepower Threat Defense (FTD) software fails to properly parse SIP traffic, which can allow an attacker to trigger high CPU usage, resulting in a denial-of-service condition on affected devices. This vulnerability is exposed if SIP Inspection is enabled on affected devices, which is the default configuration on ASA devices. The Cisco SIP Inspection feature is advertised to "... enforce the sanity of the SIP messages, as well as detect SIP-based attacks."

Impact

By causing an affected Cisco device to parse specially-crafted SIP traffic, a remote, unauthenticated attacker may be able to trigger a denial-of-service condition on affected devices.

Solution

The CERT/CC is currently unaware of a practical solution to this problem. Please consider the following workarounds:

Disable SIP Inspection

According to the Cisco advisory:

    Disabling SIP inspection will completely close the attack vector for this vulnerability. However, it may not be suitable for all customers. In particular, disabling SIP inspection would break SIP connections if either NAT is applied to SIP traffic or if not all ports required for SIP communication are opened via ACL.

    To disable SIP inspection, configure the following:

    Cisco ASA Software and Cisco FTD Software Releases 6.2 and later (in FTD 6.2 and later use Cisco FMC to add the following via FlexConfig policy):

    ┬ ┬ policy-map global_policy
    ┬ ┬ ┬ class inspection_default
    ┬ ┬ ┬ no inspect sip

    Cisco FTD Software Releases prior to 6.2:

    configure inspection sip disable

Vendor Information (Learn More)

VendorStatusDate NotifiedDate Updated
CiscoAffected-01 Nov 2018
If you are a vendor and your product is affected, let us know.

CVSS Metrics (Learn More)

GroupScoreVector
Base7.8AV:N/AC:L/Au:N/C:N/I:N/A:C
Temporal7.4E:H/RL:W/RC:C
Environmental5.5CDP:ND/TD:M/CR:ND/IR:ND/AR:ND

References

  • https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20181031-asaftd-sip-dos
  • https://www.cisco.com/c/en/us/products/security/adaptive-security-appliance-asa-software/index.html
  • https://www.cisco.com/c/en/us/support/docs/security/asa-5500-x-series-firewalls/212420-configure-firepower-threat-defense-ftd.html
  • https://www.cisco.com/c/en/us/td/docs/security/asa/asa96/configuration/firewall/asa-96-firewall-config/inspect-voicevideo.html#ID-2096-00000613
  • https://www.cisco.com/c/en/us/td/docs/security/asa/asa99/configuration/firewall/asa-99-firewall-config/inspect-voicevideo.pdf
  • https://en.wikipedia.org/wiki/Session_Initiation_Protocol

Credit

This vulnerability was publicly reported by Cisco.

This document was written by Will Dormann.

Other Information

  • CVE IDs:CVE-2018-15454
  • Date Public:31 Oct 2018
  • Date First Published:01 Nov 2018
  • Date Last Updated:05 Nov 2018
  • Document Revision:25

Feedback

If you have feedback, comments, or additional information about this vulnerability, please send us email.

Original Source

Url : http://www.kb.cert.org/vuls/id/339704

Snort® IPS/IDS

DateDescription
2018-12-04SIP wildcard VIA address flood attempt
RuleID : 48265 - Revision : 2 - Type : PROTOCOL-VOIP
2018-12-04SIP wildcard VIA address flood attempt
RuleID : 48264 - Revision : 2 - Type : PROTOCOL-VOIP
2014-01-10SIP REGISTER flood attempt
RuleID : 20395 - Revision : 5 - Type : PROTOCOL-VOIP
2014-01-10SIP REGISTER flood attempt
RuleID : 19389 - Revision : 8 - Type : PROTOCOL-VOIP

Nessus® Vulnerability Scanner

DateDescription
2018-11-08Name : The remote device is missing a vendor-supplied security patch.
File : cisco-sa-20181031-asaftd-sip-dos-asa.nasl - Type : ACT_GATHER_INFO
2018-11-08Name : The packet inspection software installed on the remote host is affected by a ...
File : cisco-sa-20181031-asaftd-sip-dos-ftd.nasl - Type : ACT_GATHER_INFO

Alert History

If you want to see full details history, please login or register.
0
1
2
3
4
5
DateInformations
2018-11-05 21:18:35
  • Multiple Updates
2018-11-02 17:18:06
  • Multiple Updates
2018-11-02 00:18:28
  • Multiple Updates
2018-11-01 21:18:34
  • Multiple Updates
2018-11-01 17:21:39
  • Multiple Updates
2018-11-01 17:18:05
  • First insertion