CVE-2014-3675 in Shim
Summary
by MITRE
Shim allows remote attackers to cause a denial of service (out-of-bounds read) via a crafted DHCPv6 packet.
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Analysis
by VulDB Data Team • 03/30/2022
The vulnerability identified as CVE-2014-3675 resides within the shim component of network infrastructure software, specifically affecting systems that process DHCPv6 (Dynamic Host Configuration Protocol for IPv6) communications. This flaw represents a critical security weakness that can be exploited by remote attackers to execute denial of service attacks through carefully crafted malicious DHCPv6 packets. The shim component serves as a protocol translation layer that facilitates communication between different network protocols, making it a crucial element in network infrastructure systems where IPv6 configuration management occurs.
The technical implementation of this vulnerability stems from improper input validation within the DHCPv6 packet processing logic of the shim module. When the system receives a malformed DHCPv6 packet containing out-of-bounds data structures or malformed option fields, the parsing routine fails to properly validate buffer boundaries before accessing memory locations. This results in an out-of-bounds read condition where the application attempts to access memory regions beyond the allocated buffer space, leading to unpredictable behavior and system instability. The vulnerability specifically manifests when processing DHCPv6 Reply messages that contain crafted option data sequences that exceed expected parameter limits, triggering the memory access violation.
From an operational perspective, this vulnerability presents a significant risk to network infrastructure availability and reliability. Remote attackers can exploit this flaw without requiring authentication or privileged access, making it particularly dangerous in environments where network services are exposed to untrusted networks. The denial of service impact can result in complete service interruption for affected systems, potentially causing cascading failures in network operations where multiple devices rely on proper DHCPv6 functionality. Network administrators may observe sudden service disruptions, system crashes, or performance degradation across affected infrastructure components that depend on the shim for protocol translation services.
The vulnerability aligns with CWE-125, which categorizes out-of-bounds read flaws as a common weakness in software security implementations. This classification emphasizes the fundamental nature of buffer overflow vulnerabilities within network protocol processing code, where insufficient bounds checking allows attackers to manipulate memory access patterns. The attack vector follows patterns consistent with the ATT&CK framework's privilege escalation and denial of service techniques, specifically targeting network infrastructure components that process external communications. Organizations should consider implementing network segmentation strategies and ingress filtering to limit the attack surface of vulnerable systems.
Mitigation strategies should focus on immediate software patching and deployment of vendor-provided security updates that address the buffer validation issues in the DHCPv6 processing routines. Network administrators should also implement monitoring solutions that can detect anomalous DHCPv6 traffic patterns and automatically alert on potential exploitation attempts. Additional protective measures include configuring firewalls to restrict DHCPv6 traffic to trusted network segments, implementing rate limiting on DHCPv6 message processing, and establishing robust network intrusion detection systems that can identify malformed packet structures. Regular security assessments of network infrastructure components and comprehensive vulnerability scanning should be conducted to identify similar weaknesses in other protocol translation modules that may present analogous security risks.