CVE-2021-0267 : Vulnerability Insights and Analysis
Learn about CVE-2021-0267, an Improper Input Validation vulnerability in Juniper Networks Junos OS allowing a DoS attack. Find details, impacted versions, and mitigation steps.
A detailed overview of CVE-2021-0267 focusing on an Improper Input Validation vulnerability in Juniper Networks Junos OS.
Understanding CVE-2021-0267
This CVE identifies a vulnerability in Juniper Networks Junos OS that allows an attacker to trigger a Denial of Service (DoS) by sending a crafted DHCP packet to crash the jdhcpd DHCP service.
What is CVE-2021-0267?
CVE-2021-0267 is an Improper Input Validation vulnerability in the active-lease query section of JDHCPD's DHCP Relay Agent in Junos OS. It enables a DoS attack by exploiting this flaw.
The Impact of CVE-2021-0267
The vulnerability can result in a sustained Denial of Service (DoS) by crashing the jdhcpd DHCP service, affecting certain versions of the Junos OS.
Technical Details of CVE-2021-0267
This section will cover the vulnerability description, affected systems and versions, and the exploitation mechanism.
Vulnerability Description
The flaw allows an attacker to crash the jdhcpd DHCP service by sending a specifically crafted DHCP packet, leading to a DoS condition.
Affected Systems and Versions
Juniper Networks Junos OS versions 19.4R3-S1, 20.1R2-S1, 20.1R3, 20.2R3, and 20.3R2 are affected by this vulnerability.
Exploitation Mechanism
The vulnerability can be exploited by sending a malicious DHCP packet to the device, causing a crash and initiating a DoS attack.
Mitigation and Prevention
This section provides guidance on immediate steps to take, long-term security practices, and the importance of patching and updates.
Immediate Steps to Take
Users are advised to update to fixed software releases to prevent exploitation of this vulnerability.
Long-Term Security Practices
Implement strong network security measures and monitor for any suspicious DHCP packet activities to mitigate potential risks.
Patching and Updates
Juniper Networks has released software updates, including Junos OS versions 19.4R3-S1, 20.1R2-S1, 20.1R3, 20.2R3, 20.3R2, and 20.4R1, to address this specific issue.