This is a BUG of dhcpd.
BUG details:
A race condition. When SDWAN is rebooted. DHCP daemon is started too quickly to retrieve the interface information. Because interface hasn’t been UP yet.
Tag: Dynamic Host Configuration Protocol
Cisco IOS XE Software for Cisco cBR-8 Converged Broadband Routers DHCP Denial of Service Vulnerability
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
Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.
This advisory is available at the following link:
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxe-dhcp-dos-JSCKX43h
This advisory is part of the September 24, 2020, release of the Cisco IOS and IOS XE Software Security Advisory Bundled Publication, which includes 25 Cisco Security Advisories that describe 34 vulnerabilities. For a complete list of the advisories and links to them, see Cisco Event Response: September 2020 Semiannual Cisco IOS and IOS XE Software Security Advisory Bundled Publication.
Security Impact Rating: High
CVE: CVE-2020-3509
Related:
“Target Device boot fails with error PXE-E55 : ProxyDHCP service did not reply to request on port 4011″
The Option 60 is configured with the string “PXEClient”. This is telling the DHCP Clients that the target of Option 66 is a PXE Client and not a PXE Server.
To resolve this issue, edit Option 60 and clear the field and restart the DHCP Server.
Related:
Cisco Prime Network Registrar DHCP Denial of Service Vulnerability
A vulnerability in the DHCP server of Cisco Prime Network Registrar could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device.
The vulnerability is due to insufficient input validation of incoming DHCP traffic. An attacker could exploit this vulnerability by sending a crafted DHCP request to an affected device. A successful exploit could allow the attacker to cause a restart of the DHCP server process, causing a DoS condition.
Cisco has released software updates that address this vulnerability. There are workarounds that address this vulnerability.
This advisory is available at the following link:
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-cpnr-dhcp-dos-BkEZfhLP
Security Impact Rating: High
CVE: CVE-2020-3272
Related:
Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software DHCP Denial of Service Vulnerability
A vulnerability in the DHCP module of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on the affected device.
The vulnerability is due to incorrect processing of certain DHCP packets. An attacker could exploit this vulnerability by sending a crafted DHCP packet to the affected device. A successful exploit could allow the attacker to cause a DoS condition on the affected device.
Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.
This advisory is available at the following link:
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-dos-qk8cTGLz
Security Impact Rating: Medium
CVE: CVE-2020-3306
Related:
PXE – symantec network boot service x86pc preboot invalid dhcp option format
I need a solution
Hi,
I have with boot from PXE.
Altiris server – windows server 2016
DHCP server – Centos 7
If the computer has same IP subnet as servers – same error.
Thank you
0
Related:
Cisco SPA122 ATA with Router Devices DHCP Services Cross-Site Scripting Vulnerability
A vulnerability in the web-based management interface of Cisco SPA122 ATA with Router Devices could allow an unauthenticated, adjacent attacker to conduct cross-site scripting attacks.
The vulnerability is due to insufficient validation of user-supplied input by the web-based management interface of the affected software. An attacker could exploit this vulnerability by sending malicious input to the affected software through crafted DHCP requests, and then persuading a user to click a crafted link. A successful exploit could allow the attacker to execute arbitrary script code in the context of the affected interface or access sensitive, browser-based information.
There are no workarounds that address this vulnerability.
This advisory is available at the following link:
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20191016-spa-dhcp-xss
Security Impact Rating: Medium
CVE: CVE-2019-12703
Related:
Arp Cache Poison being blocked on Mac
I need a solution
Anyone have any Macs in their environment that get these blocks? Seems this is happening when the Mac is connected via wireless and then connects to a wired network, making the mac address table get dhcp for the same IP with different mac addresses.
0
Related:
Post Distribution Services Are Disabled
I need a solution
Very similar to an issue discussed here but I didn’t want to ressurect a dead thread.
After distributing an image to a HP Z6 G4 workstation the machine will not complete its configuration. When I visit the machine and login using a local administrator account I find that the “DHCP Client (dhcp)” and “TCP/IP NetBIOS Helper (lmhosts)” services are set to disabled. If I configure both services to “Automatic”, restart, and then have Ghost perform a domain join everything appears normal.
The first time this happened I thought it was a misconfiguration issue from trying to capture and distribute an already established/dirty image. The second, and most recent, time I created an entirely new build from scratch but experienced the same results.
Similar to the linked thread the machine in question has two NICs. The first is listed as a Intel(R) Ethernet Connection (3) I219-LM and is disconnected and not in use. The second is a Intel(R) Ethernet Connection X722 for 1GbE.
Also similarly the image was created without using Sysprep against a Windows 10 Build 1903 system.
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Related:
Automation boot fails with Boot Disk creator
I need a solution
Using Ghost Solution 3.3 and just updated my preboot environment. At first, the machine complained about the NIC drivers with “Restarting DHCP clilent service” when booting from the automation folder. I updated them, reinstalled the automation folder and was able to complete my task.
However, when I created a bootable USB with the automation folder from the same environment, I got the the “Restarting DHCP clilent service.” Again, it’s the same environment, yet I get an error when creating a USB. I’ve created the bootable USB by using the boot disk creator and trying an ISO. Thoughts?
Because I was able to boot into it and deploy images, I know it works. I’m jsut not sure why the USB isn’t working.
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