Vulnerability Name:

CVE-2020-3509 (CCN-188807)

Assigned:2019-12-12
Published:2019-12-12
Updated:2020-10-08
Summary:A vulnerability in the DHCP message handler of Cisco IOS XE Software for Cisco cBR-8 Converged Broadband Routers could allow an unauthenticated, remote attacker to cause the supervisor to crash, which could result in a denial of service (DoS) condition. The vulnerability is due to insufficient error handling when DHCP version 4 (DHCPv4) messages are parsed. An attacker could exploit this vulnerability by sending a malicious DHCPv4 message to or through a WAN interface of an affected device. A successful exploit could allow the attacker to cause a reload of the affected device.
Note: On Cisco cBR-8 Converged Broadband Routers, all of the following are considered WAN interfaces: 10 Gbps Ethernet interfaces 100 Gbps Ethernet interfaces Port channel interfaces that include multiple 10 and/or 100 Gbps Ethernet interfaces
CVSS v3 Severity:8.6 High (CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H)
7.5 High (Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope:Scope (S): Changed
Impact Metrics:Confidentiality (C): None
Integrity (I): None
Availibility (A): High
8.6 High (CCN CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H)
7.5 High (CCN Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope:Scope (S): Changed
Impact Metrics:Confidentiality (C): None
Integrity (I): None
Availibility (A): High
CVSS v2 Severity:7.8 High (CVSS v2 Vector: AV:N/AC:L/Au:N/C:N/I:N/A:C)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Low
Authentication (Au): None
Impact Metrics:Confidentiality (C): None
Integrity (I): None
Availibility (A): Complete
7.8 High (CCN CVSS v2 Vector: AV:N/AC:L/Au:N/C:N/I:N/A:C)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Low
Athentication (Au): None
Impact Metrics:Confidentiality (C): None
Integrity (I): None
Availibility (A): Complete
Vulnerability Type:CWE-203
Vulnerability Consequences:Denial of Service
References:Source: MITRE
Type: CNA
CVE-2020-3509

Source: XF
Type: UNKNOWN
cisco-cve20203509-dos(188807)

Source: CCN
Type: Cisco Security Advisory cisco-sa-iosxe-dhcp-dos-JSCKX43h
Cisco IOS XE Software for Cisco cBR-8 Converged Broadband Routers DHCP Denial of Service Vulnerability

Source: CISCO
Type: Vendor Advisory
20200924 Cisco IOS XE Software for Cisco cBR-8 Converged Broadband Routers DHCP Denial of Service Vulnerability

Vulnerable Configuration:Configuration 1:
  • cpe:/o:cisco:ios_xe:16.7(1):*:*:*:*:*:*:*
  • AND
  • cpe:/h:cisco:cbr-8:-:*:*:*:*:*:*:*

  • Configuration CCN 1:
  • cpe:/o:cisco:ios_xe_software:*:*:*:*:*:*:*:*

  • * Denotes that component is vulnerable
    BACK
    cisco ios xe 16.7(1)
    cisco cbr-8 -
    cisco ios xe software *