CVE-2013-3232 in Linux
Summary
by MITRE
The nr_recvmsg function in net/netrom/af_netrom.c in the Linux kernel before 3.9-rc7 does not initialize a certain data structure, which allows local users to obtain sensitive information from kernel stack memory via a crafted recvmsg or recvfrom system call.
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Analysis
by VulDB Data Team • 05/10/2021
The vulnerability identified as CVE-2013-3232 resides within the Linux kernel's NetROM protocol implementation, specifically in the nr_recvmsg function located in net/netrom/af_netrom.c. This flaw represents a classic information disclosure vulnerability that affects systems running Linux kernel versions prior to 3.9-rc7. The NetROM protocol is part of the AX.25 packet radio networking stack, designed for amateur radio communications and specialized networking applications. The vulnerability manifests when the kernel fails to properly initialize a critical data structure during the processing of network messages, creating a pathway for unauthorized information extraction from kernel memory spaces.
The technical nature of this vulnerability stems from improper initialization of kernel data structures during the recvmsg and recvfrom system call processing. When a local user crafts a malicious system call to the NetROM socket interface, the nr_recvmsg function does not adequately clear or initialize memory areas that are subsequently returned to user space. This incomplete initialization leaves remnants of previously stored kernel data, including potentially sensitive information such as cryptographic keys, passwords, or other confidential system details, accessible to the unprivileged user. The vulnerability is classified as a local information disclosure issue, meaning it requires local system access but does not need network connectivity to exploit. According to CWE-665, this represents an improper initialization of a resource, which is a well-documented weakness in software development practices. The flaw aligns with ATT&CK technique T1005 which involves data from local system, and T1059 which covers command and scripting interpreter, as local users can leverage this vulnerability to extract sensitive kernel memory contents.
The operational impact of CVE-2013-3232 extends beyond simple information disclosure, as the leaked kernel memory could contain critical system information that might aid in subsequent exploitation attempts. An attacker with local access could potentially extract cryptographic keys, session tokens, or other sensitive data that could compromise system integrity and confidentiality. The vulnerability affects systems where the NetROM protocol is enabled, which includes specialized radio communication systems, amateur radio networks, and certain embedded networking solutions. While the attack vector requires local system access, the potential for privilege escalation or further exploitation makes this vulnerability particularly concerning in environments where local access is possible or where the system operates in security-sensitive contexts. Organizations running affected kernel versions should prioritize patching to prevent potential exploitation, as the vulnerability could serve as a stepping stone for more sophisticated attacks. The remediation involves upgrading to Linux kernel version 3.9-rc7 or later, where the improper initialization has been corrected through proper memory clearing mechanisms before returning data to user space processes.