VDB-124867 · CVE-2018-0476 · BID 105419

Cisco IOS XE NAT SIP ALG resource management

CVSS Meta Temp Score
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CTI Interest Score
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5.5$0-$5k0.00

A vulnerability classified as critical was found in Cisco IOS XE (Router Operating System) (affected version unknown). Affected by this vulnerability is an unknown functionality of the component NAT SIP ALG. The manipulation with an unknown input leads to a resource management vulnerability. The CWE definition for the vulnerability is CWE-399. As an impact it is known to affect availability. The summary by CVE is:

A vulnerability in the Network Address Translation (NAT) Session Initiation Protocol (SIP) Application Layer Gateway (ALG) of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload. The vulnerability is due to improper processing of SIP packets in transit while NAT is performed on an affected device. An unauthenticated, remote attacker could exploit this vulnerability by sending crafted SIP packets via UDP port 5060 through an affected device that is performing NAT for SIP packets. A successful exploit could allow an attacker to cause the device to reload, resulting in a denial of service (DoS) condition.

The bug was discovered 09/26/2018. The weakness was disclosed 10/05/2018 as cisco-sa-20180926-sip-alg as confirmed advisory (Website). It is possible to read the advisory at tools.cisco.com. This vulnerability is known as CVE-2018-0476 since 11/26/2017. The attack can be launched remotely. The exploitation doesn't need any form of authentication. The technical details are unknown and an exploit is not publicly available. The advisory points out:

The vulnerability is due to improper processing of SIP packets in transit while NAT is performed on an affected device. An unauthenticated, remote attacker could exploit this vulnerability by sending crafted SIP packets via UDP port 5060 through an affected device that is performing NAT for SIP packets. A successful exploit could allow an attacker to cause the device to reload, resulting in a denial of service (DoS) condition.

The vulnerability scanner Nessus provides a plugin with the ID 117954 (Cisco IOS XE Software NAT SIP Application Layer Gateway DoS Vulnerability (cisco-sa-20180926-sip-alg)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family CISCO and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 316323 (Cisco IOS XE Software NAT Session Initiation Protocol Application Layer Gateway Denial of Service Vulnerability(cisco-sa-20180926-sip-alg)).

Upgrading eliminates this vulnerability. A possible mitigation has been published even before and not after the disclosure of the vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (117954). The entries 124870, 124869, 124868 and 124863 are pretty similar.

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB CVSS-B Score: 🔍
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CVSSv3info

VulDB Meta Base Score: 5.6
VulDB Meta Temp Score: 5.5

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 5.9
NVD Vector: 🔍

CVSSv2info

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VulDB Base Score: 🔍
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Exploitinginfo

Class: Resource management
CWE: CWE-399 / CWE-404
CAPEC: 🔍
ATT&CK: 🔍

Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

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Current Price Estimation: 🔍

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Nessus ID: 117954
Nessus Name: Cisco IOS XE Software NAT SIP Application Layer Gateway DoS Vulnerability (cisco-sa-20180926-sip-alg)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

Interest: 🔍
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Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Timelineinfo

11/26/2017 🔍
09/26/2018 +303 days 🔍
09/26/2018 +0 days 🔍
09/26/2018 +0 days 🔍
10/05/2018 +8 days 🔍
10/05/2018 +0 days 🔍
10/05/2018 +0 days 🔍
10/06/2018 +1 days 🔍
05/22/2023 +1689 days 🔍

Sourcesinfo

Vendor: cisco.com

Advisory: cisco-sa-20180926-sip-alg
Status: Confirmed

CVE: CVE-2018-0476 (🔍)
OVAL: 🔍

SecurityTracker: 1041734
SecurityFocus: 105419 - Cisco IOS XE Software CVE-2018-0476 Denial of Service Vulnerability

scip Labs: https://www.scip.ch/en/?labs.20150108
See also: 🔍

Entryinfo

Created: 10/06/2018 10:52
Updated: 05/22/2023 13:28
Changes: 10/06/2018 10:52 (74), 03/31/2020 20:07 (4), 05/22/2023 13:28 (4)
Complete: 🔍

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