CVE-2013-7263 in Linux
Summary
by MITRE
The Linux kernel before 3.12.4 updates certain length values before ensuring that associated data structures have been initialized, which allows local users to obtain sensitive information from kernel stack memory via a (1) recvfrom, (2) recvmmsg, or (3) recvmsg system call, related to net/ipv4/ping.c, net/ipv4/raw.c, net/ipv4/udp.c, net/ipv6/raw.c, and net/ipv6/udp.c.
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Analysis
by VulDB Data Team • 06/09/2021
This vulnerability exists in Linux kernel versions prior to 3.12.4 and represents a classic information disclosure flaw that occurs when the kernel fails to properly initialize data structures before processing certain network system calls. The issue specifically affects the ping, raw, and udp network protocols across both ipv4 and ipv6 implementations, creating a pathway for local attackers to extract sensitive data from kernel stack memory through carefully crafted recvfrom, recvmmsg, or recvmsg system calls. The root cause lies in the kernel's handling of length parameters where certain values are updated before corresponding data structures have been properly initialized, leaving residual data in memory that can be inadvertently exposed to userspace processes.
The technical implementation of this vulnerability stems from improper memory management within kernel network subsystems where length fields are manipulated before ensuring that associated buffers and data structures are properly set up. This creates a race condition or initialization gap that allows attackers to read uninitialized memory contents, potentially exposing kernel stack contents, sensitive configuration data, or other confidential information that should remain protected within kernel space. The vulnerability affects multiple network protocol implementations including ping.c, raw.c, udp.c for both ipv4 and ipv6 stacks, making it particularly concerning as it spans across fundamental networking components. According to the CWE classification, this maps to CWE-248 Uncaught Exception, as the kernel fails to properly handle the initialization sequence, and the ATT&CK framework would categorize this under T1005 Data from Local System, as it enables local information disclosure through kernel memory access.
The operational impact of CVE-2013-7263 is significant for local attackers who can leverage this vulnerability to gain access to sensitive kernel memory contents, potentially including cryptographic keys, network credentials, system configuration details, or other confidential information that should remain isolated within kernel space. While the vulnerability requires local access and does not enable remote exploitation, it represents a serious privilege escalation vector that could allow attackers to gather intelligence about the system's internal state. The exposure of kernel stack memory could reveal information about kernel data structures, memory layout, or even sensitive values that might aid in further exploitation attempts. Organizations running affected kernel versions should consider this vulnerability as a medium to high severity risk, particularly in environments where local access is possible or where system confidentiality is paramount.
Mitigation strategies for this vulnerability center around kernel version updates to 3.12.4 or later, which contain the necessary patches to properly initialize data structures before updating length parameters. System administrators should prioritize patching affected systems, especially those running older kernel versions where local access might be possible through compromised accounts or services. Additionally, implementing proper access controls to limit local user privileges and monitoring for unusual network system call patterns could help detect potential exploitation attempts. The vulnerability highlights the importance of proper initialization sequences in kernel code and demonstrates how seemingly minor memory management issues can lead to significant information disclosure risks, emphasizing the need for thorough code review processes and adherence to secure coding practices in kernel development.