CVE-2015-8915 in libarchive
Summary
by MITRE
bsdcpio in libarchive before 3.2.0 allows remote attackers to cause a denial of service (invalid read and crash) via crafted cpio file.
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Analysis
by VulDB Data Team • 09/19/2022
The vulnerability identified as CVE-2015-8915 affects the bsdcpio component within libarchive library versions prior to 3.2.0, representing a critical security flaw that enables remote attackers to execute denial of service attacks through carefully constructed cpio archive files. This vulnerability specifically targets the archive extraction functionality that processes cpio format archives, which are commonly used for packaging and distributing software components across various operating systems including unix-like systems and linux distributions. The flaw stems from inadequate input validation mechanisms within the bsdcpio utility that fails to properly handle malformed or crafted archive entries, leading to unpredictable behavior during the extraction process.
The technical implementation of this vulnerability involves a buffer over-read condition that occurs when the bsdcpio utility attempts to parse maliciously crafted cpio archive entries. When processing these malformed archives, the utility reads memory locations beyond the intended buffer boundaries, causing invalid memory access patterns that ultimately result in program crashes. This type of vulnerability falls under the CWE-125 vulnerability category, which specifically addresses out-of-bounds read conditions that can lead to system instability and potential exploitation. The vulnerability is particularly concerning because it can be triggered remotely through network-based archive processing, making it an attractive target for attackers seeking to disrupt services or compromise system availability.
From an operational perspective, this vulnerability poses significant risks to systems that rely on libarchive for processing user-supplied or third-party archives, particularly in environments where automated archive extraction occurs. The impact extends beyond simple service disruption as it can affect web applications, build systems, and automated deployment pipelines that utilize cpio format archives. Attackers can exploit this vulnerability by uploading or delivering malicious cpio files that, when processed by vulnerable systems, will cause the bsdcpio utility to crash and terminate unexpectedly. This disruption can be particularly damaging in continuous integration environments, web hosting platforms, or any system where automated archive processing is a routine operation, as it can lead to complete service outages and potential data loss.
The exploitation of CVE-2015-8915 aligns with several techniques documented in the attack framework, particularly those related to input validation attacks and denial of service vectors. This vulnerability can be leveraged as part of broader attack campaigns targeting system availability, potentially serving as a precursor to more sophisticated exploitation attempts. Organizations should prioritize immediate remediation by upgrading to libarchive version 3.2.0 or later, which includes proper input validation and bounds checking mechanisms. Additional mitigations include implementing strict archive validation policies, restricting archive processing to trusted sources, and deploying network-based intrusion detection systems that can identify and block malicious archive content. The vulnerability demonstrates the importance of maintaining up-to-date security libraries and implementing comprehensive input validation across all archive processing components to prevent similar issues from compromising system integrity and availability.