CVE-2015-5674 in FreeBSD
Summary
by MITRE
The routed daemon in FreeBSD 9.3 before 9.3-RELEASE-p22, 10.2-RC2 before 10.2-RC2-p1, 10.2-RC1 before 10.2-RC1-p2, 10.2 before 10.2-BETA2-p3, and 10.1 before 10.1-RELEASE-p17 allows remote authenticated users to cause a denial of service (assertion failure and daemon exit) via a query from a network that is not directly connected.
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Analysis
by VulDB Data Team • 06/07/2022
The vulnerability described in CVE-2015-5674 affects the routed daemon in multiple versions of FreeBSD operating systems, specifically targeting versions prior to their respective patch releases. This daemon serves as a routing daemon that maintains and distributes routing information within network environments. The flaw manifests as an assertion failure that leads to daemon termination, creating a denial of service condition that can be exploited by remote authenticated attackers. The vulnerability specifically occurs when the routed daemon processes queries from networks that are not directly connected to the system, indicating a lack of proper validation in network topology handling.
The technical nature of this vulnerability stems from inadequate input validation within the routing daemon's processing logic. When the routed daemon receives a query from a non-directly connected network, it fails to properly validate the network information and subsequently triggers an assertion failure. This assertion failure causes the daemon to terminate abruptly, resulting in the cessation of routing services and disruption of network connectivity. The vulnerability is classified as a software fault that allows for denial of service conditions, with the daemon's assertion mechanism being bypassed through crafted network queries. This represents a classic case of improper error handling and validation in network services, where the daemon fails to gracefully handle unexpected network topology information.
From an operational perspective, this vulnerability presents a significant risk to network infrastructure that relies on FreeBSD systems running the routed daemon. The remote authenticated nature of the attack means that an attacker who has gained network access can potentially disrupt routing services without requiring physical access or elevated privileges beyond network connectivity. The impact extends beyond simple service disruption as routing daemon failures can cascade through network infrastructure, affecting connectivity for multiple systems that depend on proper routing information. Network administrators may experience unexpected service outages and potential routing table inconsistencies that could lead to broader network degradation or complete connectivity failures within affected segments.
The mitigation strategies for this vulnerability involve applying the appropriate security patches released by FreeBSD for the affected versions. System administrators should immediately update their FreeBSD installations to versions that include the fix for this assertion failure in the routed daemon. Additionally, network segmentation and access controls should be implemented to limit the scope of potential attacks by restricting which authenticated users can send queries to routing daemons. Network monitoring should be enhanced to detect unusual routing daemon behavior or termination events that could indicate exploitation attempts. The vulnerability aligns with CWE-248, which describes an unchecked assertion failure in software systems, and represents a potential entry point for attackers following the ATT&CK tactic of service stoppage or denial of service.
Organizations should implement comprehensive patch management procedures to ensure timely deployment of security updates, particularly for network infrastructure services like routing daemons. The vulnerability demonstrates the importance of validating network topology information in routing protocols and highlights the need for robust error handling in network services. System administrators should also consider implementing intrusion detection systems that can monitor for anomalous routing daemon behavior or network queries that might indicate exploitation attempts. Regular security assessments of routing infrastructure should be conducted to identify potential vulnerabilities in network services that could be exploited to cause service disruption or denial of service conditions.