Free and open-source vulnerability scanner

Mageni eases for you the vulnerability scanning, assessment, and management process. It is free and open-source.

Install Now

Available for macOS, Windows, and Linux

App screenshot

CVE-2021-34737

CVE information

Published

2 years ago

Last Modified

5 months ago

CVSSv2.0 Severity

Medium

CVSSv3.1 Severity

High

Impact Analysis

Description

A vulnerability in the DHCP version 4 (DHCPv4) server feature of Cisco IOS XR Software could allow an unauthenticated, remote attacker to trigger a crash of the dhcpd process, resulting in a denial of service (DoS) condition. This vulnerability exists because certain DHCPv4 messages are improperly validated when they are processed by an affected device. An attacker could exploit this vulnerability by sending a malformed DHCPv4 message to an affected device. A successful exploit could allow the attacker to cause a NULL pointer dereference, resulting in a crash of the dhcpd process. While the dhcpd process is restarting, which may take up to approximately two minutes, DHCPv4 server services are unavailable on the affected device. This could temporarily prevent network access to clients that join the network during that time period. Note: Only the dhcpd process crashes and eventually restarts automatically. The router does not reload..

CVSSv2.0 Score

Severity
Medium
Base Score
5/10
Exploit Score
10/10
Access Vector
Network
Access Complexity
Low
Authentication Required
None
Impact Score
2.9/10
Confidentiality Impact
None
Availability Impact
Partial
Integrity Impact
None

CVSSv3.1 Score

Severity
High
Base Score
7.5/10
Exploit Score
3.9/10
Access Vector
Network
Access Complexity
Low
Privileges Required
None
Impact Score
3.6/10
Confidentiality Impact
None
Availability Impact
High
Integrity Impact
None
Scope
Unchanged
User Interaction
None

Products Affected

CPE Affected Vulnerable Excluding Edit
cpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*
  Yes
- 7.3.2
cpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*
  Yes
7.4.0 -
cpe:2.3:h:cisco:asr_9000v-v2:-:*:*:*:*:*:*:*
  No
-
cpe:2.3:h:cisco:asr_9001:-:*:*:*:*:*:*:*
  No
-
cpe:2.3:h:cisco:asr_9006:-:*:*:*:*:*:*:*
  No
-
cpe:2.3:h:cisco:asr_9010:-:*:*:*:*:*:*:*
  No
-
cpe:2.3:h:cisco:asr_9901:-:*:*:*:*:*:*:*
  No
-
cpe:2.3:h:cisco:asr_9902:-:*:*:*:*:*:*:*
  No
-
cpe:2.3:h:cisco:asr_9903:-:*:*:*:*:*:*:*
  No
-
cpe:2.3:h:cisco:asr_9904:-:*:*:*:*:*:*:*
  No
-
cpe:2.3:h:cisco:asr_9906:-:*:*:*:*:*:*:*
  No
-
cpe:2.3:h:cisco:asr_9910:-:*:*:*:*:*:*:*
  No
-
cpe:2.3:h:cisco:asr_9912:-:*:*:*:*:*:*:*
  No
-
cpe:2.3:h:cisco:asr_9922:-:*:*:*:*:*:*:*
  No
-
cpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*
  Yes
- 7.3.2
cpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*
  Yes
7.4.0 -
cpe:2.3:h:cisco:ios_xrv_9000:-:*:*:*:*:*:*:*
  No
-
cpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*
  Yes
- 7.3.2
cpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*
  Yes
7.4.0 7.4.1
cpe:2.3:h:cisco:ncs540-12z20g-sys-a:-:*:*:*:*:*:*:*
  No
-
cpe:2.3:h:cisco:ncs540-12z20g-sys-d:-:*:*:*:*:*:*:*
  No
-
cpe:2.3:h:cisco:ncs540-24z8q2c-m:-:*:*:*:*:*:*:*
  No
-
cpe:2.3:h:cisco:ncs540-24z8q2c-sys:-:*:*:*:*:*:*:*
  No
-
cpe:2.3:h:cisco:ncs540-28z4c-sys-a:-:*:*:*:*:*:*:*
  No
-
cpe:2.3:h:cisco:ncs540-28z4c-sys-d:-:*:*:*:*:*:*:*
  No
-
cpe:2.3:h:cisco:ncs540-acc-sys:-:*:*:*:*:*:*:*
  No
-
cpe:2.3:h:cisco:ncs540x-12z16g-sys-a:-:*:*:*:*:*:*:*
  No
-
cpe:2.3:h:cisco:ncs540x-12z16g-sys-d:-:*:*:*:*:*:*:*
  No
-
cpe:2.3:h:cisco:ncs540x-16z4g8q2c-a:-:*:*:*:*:*:*:*
  No
-
cpe:2.3:h:cisco:ncs540x-16z4g8q2c-d:-:*:*:*:*:*:*:*
  No
-
cpe:2.3:h:cisco:ncs540x-acc-sys:-:*:*:*:*:*:*:*
  No
-
cpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*
  Yes
- 7.3.2
cpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*
  Yes
7.4.0 7.4.1
cpe:2.3:h:cisco:ncs_5001:-:*:*:*:*:*:*:*
  No
-
cpe:2.3:h:cisco:ncs_5002:-:*:*:*:*:*:*:*
  No
-
cpe:2.3:h:cisco:ncs_5011:-:*:*:*:*:*:*:*
  No
-
cpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*
  Yes
- 7.3.2
cpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*
  Yes
7.4.0 7.4.1
cpe:2.3:h:cisco:ncs_560-4:-:*:*:*:*:*:*:*
  No
-
cpe:2.3:h:cisco:ncs_560-7:-:*:*:*:*:*:*:*
  No
-
cpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*
  Yes
- 7.3.2
cpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*
  Yes
7.4.0 7.4.1
cpe:2.3:h:cisco:ncs_5501:-:*:*:*:*:*:*:*
  No
-
cpe:2.3:h:cisco:ncs_5501-se:-:*:*:*:*:*:*:*
  No
-
cpe:2.3:h:cisco:ncs_5502:-:*:*:*:*:*:*:*
  No
-
cpe:2.3:h:cisco:ncs_5502-se:-:*:*:*:*:*:*:*
  No
-
cpe:2.3:h:cisco:ncs_5508:-:*:*:*:*:*:*:*
  No
-
cpe:2.3:h:cisco:ncs_5516:-:*:*:*:*:*:*:*
  No
-