Cisco IOS/IOS XE DHCP Messages input validation

CVSS Meta Temp Score
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CTI Interest Score
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6.9$5k-$25k0.00

Summaryinfo

A vulnerability marked as problematic has been reported in Cisco IOS and IOS XE. Impacted is an unknown function of the component DHCP Handler. The manipulation as part of Messages leads to input validation. This vulnerability is referenced as CVE-2018-0173. Remote exploitation of the attack is possible. Furthermore, an exploit is available. It is recommended to apply restrictive firewalling.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in Cisco IOS and IOS XE (Router Operating System) (the affected version is unknown). This issue affects an unknown code of the component DHCP Handler. The manipulation as part of a Messages leads to a input validation vulnerability. Using CWE to declare the problem leads to CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. Impacted is availability. The summary by CVE is:

A vulnerability in the Cisco IOS Software and Cisco IOS XE Software function that restores encapsulated option 82 information in DHCP Version 4 (DHCPv4) packets could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a Relay Reply denial of service (DoS) condition. The vulnerability exists because the affected software performs incomplete input validation of encapsulated option 82 information that it receives in DHCPOFFER messages from DHCPv4 servers. An attacker could exploit this vulnerability by sending a crafted DHCPv4 packet to an affected device, which the device would then forward to a DHCPv4 server. When the affected software processes the option 82 information that is encapsulated in the response from the server, an error could occur. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition. Cisco Bug IDs: CSCvg62754.

The bug was discovered 03/28/2018. The weakness was published 03/28/2018 as cisco-sa-20180328-dhcpr2 as confirmed advisory (Website). It is possible to read the advisory at tools.cisco.com. The identification of this vulnerability is CVE-2018-0173 since 11/27/2017. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details are unknown but an exploit is available. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 09/09/2024).

It is declared as attacked. The vulnerability scanner Nessus provides a plugin with the ID 109088 (Cisco IOS DHCP Multiple Vulnerabilities), 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 316220 (Cisco IOS and IOS XE Software DHCP Version 4 Relay Reply Denial of Service Vulnerability(cisco-sa-20180328-dhcpr2)). The CISA Known Exploited Vulnerabilities Catalog lists this issue since 03/03/2022 with a due date of 03/17/2022:

Apply updates per vendor instructions.

Addressing this vulnerability is possible by firewalling . A possible mitigation has been published immediately after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at Tenable (109088) and SecurityFocus (BID 103545†). Similar entries are available at VDB-115174 and VDB-115176. Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

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CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
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CVSSv3info

VulDB Meta Base Score: 6.9
VulDB Meta Temp Score: 6.9

VulDB Base Score: 5.3
VulDB Temp Score: 5.2
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 8.6
NVD Vector: 🔍

CVSSv2info

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Exploitinginfo

Class: Input validation
CWE: CWE-20
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Attacked

EPSS Score: 🔍
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Nessus ID: 109088
Nessus Name: Cisco IOS DHCP Multiple Vulnerabilities
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

Interest: 🔍
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Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Firewall
Status: 🔍

Reaction Time: 🔍
0-Day Time: 🔍
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Timelineinfo

11/27/2017 🔍
03/28/2018 +121 days 🔍
03/28/2018 +0 days 🔍
03/28/2018 +0 days 🔍
03/28/2018 +0 days 🔍
03/28/2018 +0 days 🔍
03/29/2018 +1 days 🔍
04/17/2018 +19 days 🔍
09/09/2024 +2337 days 🔍

Sourcesinfo

Vendor: cisco.com

Advisory: cisco-sa-20180328-dhcpr2
Researcher: Tenable
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2018-0173 (🔍)
GCVE (CVE): GCVE-0-2018-0173
GCVE (VulDB): GCVE-100-115175

OVAL: 🔍

SecurityFocus: 103545 - Cisco IOS and IOS XE Software CVE-2018-0173 Denial of Service Vulnerability
SecurityTracker: 1040591

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

Entryinfo

Created: 03/29/2018 09:14
Updated: 09/09/2024 22:29
Changes: 03/29/2018 09:14 (73), 01/17/2020 17:51 (5), 02/06/2021 12:07 (3), 02/06/2021 12:10 (1), 04/23/2024 16:46 (27), 07/24/2024 17:10 (1), 09/09/2024 22:29 (1)
Complete: 🔍
Cache ID: 216::103

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