CVE-2011-1779 in libarchive
Summary
by MITRE
Multiple use-after-free vulnerabilities in libarchive 2.8.4 and 2.8.5 allow remote attackers to cause a denial of service (application crash) or possibly have unspecified other impact via a crafted (1) TAR archive or (2) ISO9660 image.
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Analysis
by VulDB Data Team • 02/16/2019
The vulnerability identified as CVE-2011-1779 represents a critical security flaw within the libarchive library version 2.8.4 and 2.8.5, which serves as a fundamental component for handling various archive formats including tar and iso9660. This issue manifests as multiple use-after-free conditions that occur when the library processes specially crafted archive files, creating a significant risk for systems that rely on libarchive for archive manipulation and extraction operations. The vulnerability specifically affects the handling of TAR archives and ISO9660 images, which are commonly used in various operating systems and applications for data storage and distribution.
The technical root cause of this vulnerability lies in improper memory management within the libarchive library implementation. When processing maliciously constructed archive files, the library fails to properly validate the structure and content of the archive data before attempting to free memory resources that may have already been deallocated or are in an inconsistent state. This use-after-free condition occurs when the program attempts to access memory that has been freed, leading to undefined behavior that can result in application crashes or potentially more severe consequences depending on the execution context. The flaw is particularly dangerous because it can be triggered remotely through network-based archive processing operations, making it exploitable in various scenarios where archive files are automatically processed or extracted by applications.
The operational impact of CVE-2011-1779 extends beyond simple denial of service conditions, as the vulnerability could potentially enable more sophisticated attacks depending on the target environment and execution context. When applications utilizing libarchive encounter malformed archive files, the use-after-free conditions can cause unpredictable application behavior including crashes, memory corruption, or in some cases, arbitrary code execution. This vulnerability affects a wide range of systems and applications that depend on libarchive for archive handling, including but not limited to backup systems, file management utilities, and network services that process user-uploaded archives. The remote exploitability aspect means that attackers can potentially trigger these conditions without requiring local access, making the vulnerability particularly concerning for web applications and network services.
Security professionals should consider this vulnerability in the context of CWE-416, which specifically addresses use-after-free conditions, and aligns with ATT&CK technique T1203 for legitimate program execution and T1059 for command and scripting interpreter. The vulnerability demonstrates how memory safety issues in widely-used libraries can create cascading security problems across multiple systems and applications. Organizations should prioritize immediate patching of affected libarchive versions, implementing proper input validation for archive files, and monitoring for potential exploitation attempts. Additionally, system administrators should consider implementing network segmentation and access controls to limit the potential impact of successful exploitation attempts, while also ensuring that automated archive processing systems are properly hardened against malformed input. The vulnerability serves as a reminder of the critical importance of maintaining up-to-date security patches for foundational libraries that are widely distributed across various software ecosystems.