CVE-2022-32264 in FreeBSD
Summary
by MITRE • 09/06/2022
** UNSUPPORTED WHEN ASSIGNED ** sys/netinet/tcp_timer.h in FreeBSD before 7.0 contains a denial-of-service (DoS) vulnerability due to improper handling of TSopt on TCP connections. NOTE: This vulnerability only affects products that are no longer supported by the maintainer.
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Analysis
by VulDB Data Team • 08/03/2024
The vulnerability identified as CVE-2022-32264 represents a denial-of-service condition affecting FreeBSD systems prior to version 7.0, specifically within the tcp_timer.h component of the networking stack. This flaw manifests in the improper handling of TSopt parameters during TCP connection management, creating a potential avenue for attackers to disrupt network services through carefully crafted network traffic. The vulnerability resides in the kernel-level implementation of TCP timestamp options, which are used for various network protocols including protection against wrapped sequence numbers and enhanced round-trip time estimation. When systems process TCP packets containing malformed or unexpected timestamp options, the kernel's handling mechanism fails to properly validate or manage these parameters, leading to system instability or complete service disruption.
The technical exploitation of this vulnerability occurs through the manipulation of TCP timestamp options in network packets transmitted to vulnerable FreeBSD systems. The flaw stems from inadequate input validation within the tcp_timer.h module, where timestamp options are processed without proper bounds checking or error handling mechanisms. This improper handling creates a condition where malformed timestamp data can cause kernel memory corruption or infinite loop scenarios within the TCP connection state machine. The vulnerability directly maps to CWE-129, which describes improper validation of array indices, and CWE-691, which covers insufficient control of generation of code. The root cause lies in the lack of proper bounds checking when processing TCP timestamp options, allowing attackers to craft packets that trigger unexpected behavior in the kernel's TCP implementation.
From an operational perspective, this vulnerability presents a significant risk to FreeBSD systems that continue to operate legacy versions or have not received proper security updates. The denial-of-service impact can result in complete network service unavailability, requiring system reboot or manual intervention to restore normal operations. Network administrators may observe sudden connection drops, service timeouts, or complete network stack failures when this vulnerability is exploited. The attack vector is relatively straightforward, requiring only the ability to send TCP packets to the target system, making it particularly dangerous in environments where network access is not properly restricted. The vulnerability's impact extends beyond simple service disruption to potentially affecting critical infrastructure components that rely on stable TCP connectivity, including web servers, database systems, and network monitoring tools.
The recommended mitigation strategy for CVE-2022-32264 involves immediate system upgrades to FreeBSD versions 7.0 or later, where the vulnerability has been addressed through improved input validation and error handling in the TCP timestamp processing code. Organizations should implement network segmentation and access controls to limit exposure to potentially compromised systems, while also monitoring for unusual network traffic patterns that might indicate exploitation attempts. Security teams should consider implementing intrusion detection systems with signature-based detection capabilities targeting TCP timestamp anomalies. Additionally, regular security assessments and patch management programs should be enforced to ensure all systems receive timely updates, as this vulnerability represents a known weakness in legacy software versions that no longer receive security support or updates from the vendor. The ATT&CK framework categorizes this vulnerability under T1499.004 for network denial of service, highlighting the importance of maintaining up-to-date system configurations and implementing proper network monitoring to detect and prevent exploitation attempts.