CVE-2016-2037 in cpio
Summary
by MITRE
The cpio_safer_name_suffix function in util.c in cpio 2.11 allows remote attackers to cause a denial of service (out-of-bounds write) via a crafted cpio file.
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Analysis
by VulDB Data Team • 07/08/2022
The vulnerability identified as CVE-2016-2037 resides within the cpio utility version 2.11, specifically within the cpio_safer_name_suffix function located in the util.c source file. This flaw represents a critical security issue that enables remote attackers to execute a denial of service attack through manipulation of cpio archive files. The cpio utility serves as a fundamental tool for archiving and extracting files in Unix and Unix-like operating systems, making this vulnerability particularly concerning for system administrators and security professionals managing such environments. The vulnerability manifests when the utility processes specially crafted cpio archives that contain malformed data structures, leading to memory corruption issues that can crash the application and potentially disrupt system operations.
The technical root cause of this vulnerability stems from inadequate input validation and bounds checking within the cpio_safer_name_suffix function. When processing archive entries, the function fails to properly validate the length and structure of name fields within the cpio archive format. This deficiency allows attackers to construct cpio files containing oversized or malformed name fields that exceed the allocated buffer boundaries during processing. The out-of-bounds write condition occurs when the function attempts to copy or manipulate name strings without sufficient bounds checking, resulting in memory corruption that can trigger application crashes or unpredictable behavior. This type of vulnerability aligns with CWE-121, which describes heap-based buffer overflow conditions, and represents a classic example of improper input validation leading to memory safety issues.
The operational impact of CVE-2016-2037 extends beyond simple denial of service, as it can potentially be exploited in more sophisticated attack scenarios. Remote attackers can leverage this vulnerability to disrupt services that rely on cpio for archive processing, including automated backup systems, package management utilities, and system update mechanisms. The vulnerability affects systems running cpio version 2.11 and potentially earlier versions, making it relevant across a wide range of Unix-like systems including various Linux distributions, BSD implementations, and other Unix-based platforms. Security researchers have classified this vulnerability as high-risk due to its potential for remote exploitation and the widespread use of cpio across enterprise and infrastructure environments. The attack vector requires only that a victim process cpio archives from untrusted sources, which is common in scenarios involving automated package installation, system updates, or file transfer operations.
Mitigation strategies for CVE-2016-2037 primarily focus on updating the cpio utility to versions that contain the necessary patches and input validation improvements. System administrators should immediately upgrade to cpio version 2.12 or later, where the vulnerability has been addressed through enhanced bounds checking and proper input validation mechanisms. Additionally, organizations should implement defensive measures such as restricting cpio operations to trusted archives only, implementing network segmentation to limit exposure, and monitoring for suspicious archive processing activities. From an operational security perspective, the vulnerability demonstrates the importance of maintaining up-to-date system utilities and implementing robust input validation practices throughout software development lifecycle processes. The ATT&CK framework categorizes this vulnerability under the T1499.004 technique for denial of service, emphasizing the need for proper software patch management and defensive coding practices. Organizations should also consider implementing automated vulnerability scanning tools that can detect systems running vulnerable versions of cpio and generate alerts for immediate remediation. The vulnerability serves as a reminder of the critical importance of memory safety in system utilities and the potential for seemingly minor input validation flaws to result in significant security implications across enterprise environments.