CVE-2012-1583 in Linux
Summary
by MITRE
Double free vulnerability in the xfrm6_tunnel_rcv function in net/ipv6/xfrm6_tunnel.c in the Linux kernel before 2.6.22, when the xfrm6_tunnel module is enabled, allows remote attackers to cause a denial of service (panic) via crafted IPv6 packets.
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Analysis
by VulDB Data Team • 01/02/2025
The CVE-2012-1583 vulnerability represents a critical double free error in the Linux kernel's IPv6 implementation that fundamentally compromises system stability and availability. This flaw exists within the xfrm6_tunnel_rcv function located in the net/ipv6/xfrm6_tunnel.c source file, specifically affecting kernel versions prior to 2.6.22. The vulnerability manifests when the xfrm6_tunnel module is actively enabled, creating a dangerous condition where memory management operations become corrupted through improper handling of allocated resources. The double free condition occurs when the kernel's packet processing routine attempts to release the same memory block twice, leading to unpredictable behavior and potential system crashes.
The technical exploitation of this vulnerability requires remote attackers to craft specially malformed IPv6 packets that trigger the vulnerable code path within the xfrm6_tunnel module. When such packets are received and processed by an affected system, the kernel's memory allocator encounters the double free scenario, which can result in memory corruption, heap corruption, or kernel panic conditions. This type of vulnerability falls under CWE-415, which specifically addresses double free conditions in memory management operations. The flaw demonstrates how improper resource management in kernel space can be leveraged to cause system-wide denial of service, making it particularly dangerous in networked environments where attackers can remotely inject malicious traffic.
From an operational perspective, this vulnerability presents a severe risk to network infrastructure and server availability, as it allows remote attackers to induce kernel panics and system crashes without requiring local access or elevated privileges. The impact extends beyond simple service disruption to potentially compromising the integrity of networked systems, as kernel-level memory corruption can lead to unpredictable behavior and system instability. Organizations running affected kernel versions are particularly vulnerable during network traffic processing, especially when IPv6 tunneling is enabled, creating an attack surface that can be exploited by malicious actors to perform denial of service attacks against critical infrastructure.
The mitigation strategies for CVE-2012-1583 primarily focus on immediate kernel version upgrades to 2.6.22 or later, where the vulnerability has been addressed through proper memory management implementation. System administrators should also consider disabling the xfrm6_tunnel module entirely if IPv6 tunneling functionality is not required, as this eliminates the attack surface. Network segmentation and firewall rules can provide additional protection by limiting exposure to potentially malicious IPv6 traffic, though these measures do not address the root cause. The vulnerability aligns with ATT&CK technique T1499.004, which covers network denial of service attacks, and demonstrates how kernel-level flaws can be exploited to achieve system compromise without traditional exploitation vectors. Organizations must prioritize patch management and kernel security updates to prevent exploitation of this and similar vulnerabilities that could lead to broader system compromise or availability disruption.