CVE-2011-4913 in Linux
Summary
by MITRE
The rose_parse_ccitt function in net/rose/rose_subr.c in the Linux kernel before 2.6.39 does not validate the FAC_CCITT_DEST_NSAP and FAC_CCITT_SRC_NSAP fields, which allows remote attackers to (1) cause a denial of service (integer underflow, heap memory corruption, and panic) via a small length value in data sent to a ROSE socket, or (2) conduct stack-based buffer overflow attacks via a large length value in data sent to a ROSE socket.
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Analysis
by VulDB Data Team • 11/29/2024
The vulnerability identified as CVE-2011-4913 resides within the Linux kernel's ROSE protocol implementation, specifically in the rose_parse_ccitt function located in net/rose/rose_subr.c. This function processes CCITT (Consultative Committee for International Telegraph and Telephone) protocol data structures used in the ROSE (ROuting for the Extension of the X.25 protocol) networking stack. The ROSE protocol is part of the X.25 network protocol suite that was historically used in packet-switched networks, particularly in telecommunication systems. The flaw manifests in the improper validation of two critical fields: FAC_CCITT_DEST_NSAP and FAC_CCITT_SRC_NSAP, which contain destination and source network service access point identifiers respectively. These fields are essential for proper routing and identification within the X.25 network infrastructure that ROSE extends.
The technical implementation of this vulnerability stems from the absence of proper input validation mechanisms within the rose_parse_ccitt function. When processing incoming data packets containing CCITT protocol information, the function fails to validate the length values specified in the FAC_CCITT_DEST_NSAP and FAC_CCITT_SRC_NSAP fields. This lack of validation creates two distinct attack vectors that can be exploited by remote adversaries. The first vector involves sending data packets with intentionally small length values, which can trigger integer underflow conditions within the kernel's memory management routines. When integer underflow occurs, it can lead to heap memory corruption and ultimately cause the kernel to panic, resulting in a denial of service condition. The second vector exploits large length values that can cause stack-based buffer overflows, where the kernel attempts to allocate memory on the stack based on the malicious length values provided by the attacker, potentially allowing for arbitrary code execution.
From an operational impact perspective, this vulnerability represents a critical security flaw that can severely compromise system availability and potentially confidentiality. The denial of service aspect means that any system running a Linux kernel version prior to 2.6.39 with ROSE protocol support enabled becomes vulnerable to remote attacks that can bring the entire system down through kernel panics and memory corruption. The buffer overflow component presents even greater risks as it could potentially be exploited for privilege escalation or arbitrary code execution within the kernel space, making this vulnerability particularly dangerous for systems that are exposed to untrusted network traffic. The attack surface is expanded by the fact that ROSE protocol support is typically enabled in kernel configurations that support legacy telecommunication protocols, particularly in systems that maintain connectivity with older X.25 networks or in specialized telecommunication equipment.
The vulnerability maps directly to CWE-129, which describes improper validation of input bounds, and CWE-125, which covers out-of-bounds read conditions. Additionally, this flaw aligns with ATT&CK technique T1068, which involves exploiting legitimate credentials or system privileges to gain access to resources. The kernel-level nature of this vulnerability also relates to ATT&CK technique T1059, which covers command and scripting interpreter usage, as successful exploitation could potentially allow attackers to execute arbitrary commands with kernel privileges. The remediation strategy involves upgrading to Linux kernel version 2.6.39 or later, where proper input validation has been implemented in the rose_parse_ccitt function. System administrators should also consider disabling ROSE protocol support entirely if it is not required for their specific use case, as this eliminates the attack surface associated with this vulnerable implementation. The vulnerability demonstrates the importance of proper input validation in kernel space, particularly when dealing with legacy protocol implementations that may not have undergone comprehensive security review processes.