CVE-2014-2568 in Linux
Summary
by MITRE
Use-after-free vulnerability in the nfqnl_zcopy function in net/netfilter/nfnetlink_queue_core.c in the Linux kernel through 3.13.6 allows attackers to obtain sensitive information from kernel memory by leveraging the absence of a certain orphaning operation. NOTE: the affected code was moved to the skb_zerocopy function in net/core/skbuff.c before the vulnerability was announced.
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Analysis
by VulDB Data Team • 05/08/2026
The CVE-2014-2568 vulnerability represents a critical use-after-free flaw in the Linux kernel's network filtering subsystem that emerged in kernel versions through 3.13.6. This vulnerability specifically targets the nfqnl_zcopy function within the netfilter framework, which handles packet queue operations for netfilter userspace applications. The flaw stems from an insufficient orphaning operation that leaves kernel memory structures in an inconsistent state after being freed, creating opportunities for information disclosure and potential privilege escalation.
The technical implementation of this vulnerability occurs within the nfnetlink_queue_core.c file where the nfqnl_zcopy function processes packets destined for userspace queue operations. When packets are processed through the netfilter subsystem, the function fails to properly orphan memory references, leading to a scenario where freed kernel memory can still be accessed. This memory management issue creates a use-after-free condition that allows attackers to read sensitive data from kernel memory spaces, potentially exposing kernel pointers, credentials, or other confidential information that should remain protected from userspace access.
The operational impact of CVE-2014-2568 extends beyond simple information disclosure, as it can enable attackers to gather kernel memory contents that may contain sensitive data structures, cryptographic keys, or other privileged information. The vulnerability affects systems running Linux kernel versions up to 3.13.6, making it particularly concerning for organizations with older kernel versions in production environments. Attackers can leverage this flaw by crafting specific network traffic patterns that trigger the vulnerable code path, potentially leading to kernel memory leaks that could be exploited for further attacks including privilege escalation or system compromise.
This vulnerability aligns with CWE-416, which describes the use of freed memory condition, and demonstrates how improper memory management in kernel space can create persistent security weaknesses. The ATT&CK framework categorizes this as a privilege escalation technique through kernel vulnerabilities, where adversaries exploit memory corruption flaws to gain elevated system privileges. The specific nature of the flaw in the skb_zerocopy function, which was later moved from the original location, indicates that the vulnerability was part of a broader memory management pattern that required careful handling of reference counting and orphaning operations in kernel packet processing.
Mitigation strategies for CVE-2014-2568 require immediate kernel updates to versions that contain the patched implementation of the skb_zerocopy function and related memory management operations. Organizations should prioritize upgrading to kernel versions 3.13.7 or later, where the vulnerability has been addressed through proper memory orphaning procedures. Additionally, system administrators should implement network segmentation and monitoring to detect unusual packet processing patterns that might indicate exploitation attempts, while maintaining comprehensive patch management processes to ensure all affected systems receive timely security updates. The vulnerability underscores the importance of proper memory management in kernel code and demonstrates how seemingly minor implementation gaps can create significant security risks in operating system components.