CVE-2014-3688 in Linux
Summary
by MITRE
The SCTP implementation in the Linux kernel before 3.17.4 allows remote attackers to cause a denial of service (memory consumption) by triggering a large number of chunks in an association's output queue, as demonstrated by ASCONF probes, related to net/sctp/inqueue.c and net/sctp/sm_statefuns.c.
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Analysis
by VulDB Data Team • 02/27/2022
The vulnerability described in CVE-2014-3688 represents a critical memory exhaustion issue within the Linux kernel's Stream Control Transmission Protocol implementation. This flaw affects systems running kernel versions prior to 3.17.4 and specifically targets the SCTP protocol stack's handling of association output queues. The vulnerability enables remote attackers to consume excessive system memory resources through carefully crafted network traffic, ultimately leading to system instability and potential denial of service conditions. The issue stems from the kernel's inability to properly manage memory allocation when processing large volumes of SCTP chunks, particularly during association configuration procedures.
The technical root cause of this vulnerability lies in the improper handling of SCTP chunks within the kernel's network stack components located in net/sctp/inqueue.c and net/sctp/sm_statefuns.c. When remote attackers send specially crafted ASCONF (Association Configuration) probes, the SCTP implementation fails to adequately limit or throttle the number of chunks that can be queued for transmission. This results in unbounded memory growth within the kernel's output queue structures, as each chunk consumes significant memory resources. The vulnerability is particularly dangerous because it can be triggered remotely without requiring authentication or special privileges, making it an attractive target for automated attacks.
The operational impact of this vulnerability extends beyond simple memory exhaustion, creating cascading effects that can severely compromise system availability and performance. Systems utilizing SCTP for critical communications become vulnerable to sustained memory exhaustion attacks that can render them unusable for legitimate traffic. The memory consumption occurs at the kernel level, meaning that even if applications remain functional, the system may become unresponsive as kernel memory becomes depleted. This vulnerability particularly affects systems that rely on SCTP for signaling protocols, telecommunications infrastructure, or any environment where SCTP is used for reliable data transmission across networks.
Mitigation strategies for this vulnerability require immediate kernel updates to versions 3.17.4 or later where the issue has been addressed through proper memory management controls and queue limiting mechanisms. System administrators should also implement network-level controls such as rate limiting and connection tracking to reduce the impact of potential attacks. Additionally, monitoring for unusual patterns in SCTP traffic and memory consumption can help detect exploitation attempts. The vulnerability aligns with CWE-400, which addresses "Uncontrolled Resource Consumption" and specifically relates to improper handling of resource allocation in network protocol implementations. From an ATT&CK framework perspective, this vulnerability maps to T1499.004, which covers "Endpoint Denial of Service," and represents a classic example of resource exhaustion attacks that target kernel-level protocol implementations. Organizations should also consider implementing network segmentation and firewall rules to limit SCTP traffic exposure, particularly in environments where the vulnerability cannot be immediately patched.