CVE-2022-22179 in Junos OS
Summary
by MITRE • 01/19/2022
A Improper Validation of Specified Index, Position, or Offset in Input vulnerability in the Juniper DHCP daemon (jdhcpd) of Juniper Networks Junos OS allows an adjacent unauthenticated attacker to cause a crash of jdhcpd and thereby a Denial of Service (DoS). In a scenario where DHCP relay or local server is configured the problem can be triggered if a DHCPv4 packet with specific options is received leading to a corruption of the options read from the packet. This corruption can then lead to jdhcpd crash and restart. This issue affects: Juniper Networks Junos OS 17.4R1 and later versions prior to 18.4R3-S10; 19.1 versions prior to 19.1R3-S7; 19.2 versions prior to 19.2R1-S8, 19.2R3-S4; 19.3 versions prior to 19.3R3-S4; 19.4 versions prior to 19.4R3-S6; 20.1 versions prior to 20.1R3-S2; 20.2 versions prior to 20.2R3-S3; 20.3 versions prior to 20.3R3-S2; 20.4 versions prior to 20.4R3-S1; 21.1 versions prior to 21.1R2-S2, 21.1R3; 21.2 versions prior to 21.2R1-S2, 21.2R2, 21.2R3; 21.3 versions prior to 21.3R1-S1, 21.3R2.
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Analysis
by VulDB Data Team • 01/20/2022
The vulnerability CVE-2022-22179 represents a critical flaw in Juniper Networks Junos OS DHCP daemon (jdhcpd) that stems from improper validation of input parameters during DHCP packet processing. This weakness falls under the category of CWE-129 Improper Validation of Specified Index, Position, or Offset in Input, which is a fundamental security issue that occurs when applications fail to properly validate array indices, buffer offsets, or other positional parameters. The vulnerability specifically affects the jdhcpd service responsible for handling dynamic host configuration protocol messages in Juniper network devices, creating a significant attack surface for adjacent unauthenticated adversaries.
The technical exploitation of this vulnerability occurs when an attacker sends specially crafted DHCPv4 packets containing malformed options to a Juniper device with DHCP relay or local server functionality enabled. The jdhcpd daemon processes these packets without adequate validation of the option offsets or indices within the DHCP message structure, leading to memory corruption when attempting to read the malformed option data. This corruption directly impacts the internal data structures used by jdhcpd to parse and handle DHCP options, ultimately causing the daemon to crash and restart automatically. The issue is particularly concerning because it requires no authentication and can be triggered from adjacent network segments, making it accessible to local network attackers who may not have direct access to the device itself.
The operational impact of this vulnerability extends beyond simple service disruption, as it creates a persistent denial of service condition that can significantly impact network operations. Network administrators may experience intermittent connectivity issues as the jdhcpd service restarts repeatedly, potentially disrupting critical network services that depend on dynamic IP address allocation. The vulnerability affects a wide range of Junos OS versions, spanning from 17.4R1 through 21.3 releases, indicating that organizations running these older versions are at risk. This widespread impact across multiple release branches suggests that the flaw was introduced early in the codebase and persisted through numerous updates, requiring comprehensive patch management across affected network infrastructure.
Organizations can mitigate this vulnerability through several approaches that align with established cybersecurity frameworks and best practices. The primary remediation involves applying the official Juniper security patches that address the specific input validation issues in jdhcpd, particularly targeting the affected version ranges mentioned in the advisory. Network segmentation and access control measures can help reduce the attack surface by limiting adjacent network access to devices running DHCP services. The implementation of network monitoring solutions that can detect anomalous DHCP traffic patterns may provide early warning of potential exploitation attempts. Additionally, organizations should consider implementing DHCP snooping and other network access control mechanisms that can help prevent unauthorized DHCP packets from reaching vulnerable devices, thereby reducing the likelihood of successful exploitation.
This vulnerability demonstrates the importance of proper input validation in network service implementations and aligns with ATT&CK technique T1499.004 Network Denial of Service, where attackers exploit weaknesses in network protocols to cause service disruption. The flaw also relates to ATT&CK technique T1071.004 Application Layer Protocol: DNS, as DHCP and DNS services often work together in network infrastructure, making proper validation across all protocol layers essential for overall network security. Organizations should implement comprehensive vulnerability management programs that include regular security assessments of network infrastructure components, particularly services that handle untrusted input from adjacent network segments. The incident also highlights the need for robust software development practices that emphasize input validation, buffer overflow protection, and proper error handling in network services to prevent similar vulnerabilities from being introduced in future releases.