CVE-2020-27336 in IPv6
Summary
by MITRE • 12/23/2020
An issue was discovered in Treck IPv6 before 6.0.1.68. Improper input validation in the IPv6 component when handling a packet sent by an unauthenticated remote attacker could result in an out-of-bounds read of up to three bytes via network access.
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Analysis
by VulDB Data Team • 09/30/2025
The vulnerability identified as CVE-2020-27336 affects the Treck IPv6 implementation prior to version 6.0.1.68, representing a critical security flaw that undermines the integrity of network communications. This issue stems from inadequate input validation mechanisms within the IPv6 processing component, specifically when handling packets transmitted by unauthenticated remote attackers. The flaw manifests as an out-of-bounds read condition that can potentially expose sensitive data or disrupt system operations through network-based attacks. The vulnerability's classification aligns with CWE-125, which addresses out-of-bounds read conditions in software implementations, making it a significant concern for network infrastructure security.
The technical exploitation of this vulnerability occurs when an unauthenticated remote attacker sends specially crafted IPv6 packets to a vulnerable system. The improper input validation in the Treck IPv6 component fails to properly sanitize or validate incoming packet data, allowing an attacker to trigger an out-of-bounds memory read operation. This specific read access extends up to three bytes beyond the intended memory boundaries, potentially exposing system memory contents that could contain sensitive information such as cryptographic keys, session tokens, or other confidential data. The vulnerability's impact is amplified by its network accessibility, meaning attackers do not require local system access or authentication credentials to exploit the flaw, making it particularly dangerous in exposed network environments.
From an operational perspective, this vulnerability creates substantial risks for organizations relying on Treck IPv6 implementations, particularly those with exposed network services or systems operating in untrusted network environments. The out-of-bounds read condition could lead to information disclosure, system instability, or potentially serve as a stepping stone for more sophisticated attacks. The vulnerability's presence in IPv6 implementations is particularly concerning given the increasing adoption of IPv6 networks and the critical role these protocols play in modern network infrastructure. Organizations may experience service disruptions or data breaches if this vulnerability remains unpatched, especially in environments where network monitoring and intrusion detection systems might not immediately detect such subtle memory access violations.
The recommended mitigation strategy centers on immediate deployment of the vendor-provided patch or update to Treck IPv6 version 6.0.1.68 or later, which addresses the input validation flaws that enable the out-of-bounds read condition. Network administrators should also implement additional defensive measures including network segmentation, access control lists, and monitoring for anomalous IPv6 traffic patterns that might indicate exploitation attempts. The vulnerability's characteristics align with ATT&CK technique T1071.004, which covers application layer protocol traffic, and may require enhanced network monitoring to detect potential exploitation attempts. Organizations should also conduct thorough vulnerability assessments to identify all systems running affected Treck IPv6 implementations and prioritize remediation efforts based on risk exposure and network criticality.