CVE-2010-4160 in Linux
Summary
by MITRE
Multiple integer overflows in the (1) pppol2tp_sendmsg function in net/l2tp/l2tp_ppp.c, and the (2) l2tp_ip_sendmsg function in net/l2tp/l2tp_ip.c, in the PPPoL2TP and IPoL2TP implementations in the Linux kernel before 2.6.36.2 allow local users to cause a denial of service (heap memory corruption and panic) or possibly gain privileges via a crafted sendto call.
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Analysis
by VulDB Data Team • 07/01/2024
The vulnerability identified as CVE-2010-4160 represents a critical security flaw affecting the Linux kernel's implementation of Point-to-Point Protocol over Layer 2 Tunneling Protocol. This vulnerability exists in two distinct functions within the kernel's network layer implementation, specifically within the pppol2tp_sendmsg function located in net/l2tp/l2tp_ppp.c and the l2tp_ip_sendmsg function found in net/l2tp/l2tp_ip.c. These functions handle the transmission of data through PPPoL2TP and IPoL2TP protocols respectively, which are commonly used for creating virtual private networks and tunneling connections across networks.
The core technical flaw manifests as integer overflows occurring during the processing of sendto system calls directed at L2TP network endpoints. When a local user crafts a specially constructed sendto call, the kernel functions fail to properly validate input parameters, leading to arithmetic overflow conditions that result in heap memory corruption. This type of vulnerability falls under the Common Weakness Enumeration category CWE-190, which specifically addresses integer overflow and underflow conditions. The overflow conditions cause the kernel to allocate insufficient memory for data structures, resulting in memory corruption that can trigger system panics and complete denial of service conditions.
The operational impact of this vulnerability extends beyond simple denial of service to potentially enabling privilege escalation. Local attackers who can execute code on a target system can exploit these integer overflows to corrupt kernel memory structures, potentially allowing them to execute arbitrary code with kernel privileges. This represents a significant security risk as it transforms a local denial of service vulnerability into a potential privilege escalation vector. The ATT&CK framework categorizes this type of vulnerability under T1068, which involves exploiting local privilege escalation opportunities, and T1499, which covers network denial of service attacks. The vulnerability affects all Linux kernel versions prior to 2.6.36.2, making it particularly concerning given the widespread adoption of older kernel versions in enterprise environments.
The exploitation of this vulnerability requires local access to the target system, but the potential for privilege escalation makes it a serious concern for system administrators. The heap memory corruption resulting from integer overflows can lead to unpredictable system behavior, including kernel panics that require system restarts. Organizations running affected kernel versions should prioritize patching their systems, as the vulnerability can be exploited by any local user with the ability to make sendto calls to L2TP network endpoints. The fix implemented in kernel version 2.6.36.2 addresses the integer overflow conditions by adding proper input validation and bounds checking to ensure that memory allocations remain within safe limits. This vulnerability highlights the importance of proper input validation in kernel space code and demonstrates how seemingly minor flaws in network protocol implementations can have severe security implications.