CVE-2011-1777 in libarchive
Summary
by MITRE
Multiple buffer overflows in the (1) heap_add_entry and (2) relocate_dir functions in archive_read_support_format_iso9660.c in libarchive through 2.8.5 allow remote attackers to cause a denial of service (application crash) or possibly execute arbitrary code via a crafted ISO9660 image.
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Analysis
by VulDB Data Team • 12/01/2021
The vulnerability identified as CVE-2011-1777 represents a critical security flaw in the libarchive library version 2.8.5 and earlier, specifically within the ISO9660 file format handling components. This issue manifests through two distinct buffer overflow conditions located in the heap_add_entry and relocate_dir functions within the archive_read_support_format_iso9660.c source file. The affected library serves as a fundamental component for handling various archive formats including iso9660, which is commonly used for optical disc images and is widely implemented across operating systems and security tools for archive extraction and manipulation.
The technical implementation of this vulnerability stems from inadequate input validation and memory management within the ISO9660 parsing logic. When processing maliciously crafted ISO9660 images, the heap_add_entry function fails to properly bounds-check data structures before copying or allocating memory, while the relocate_dir function similarly lacks proper validation of directory relocation parameters. These buffer overflows occur during the parsing of ISO9660 metadata structures where attacker-controlled data is directly used to determine memory allocation sizes or buffer copy operations without adequate sanitization. The vulnerability falls under CWE-121, which categorizes buffer overflow conditions where insufficient boundary checks allow attackers to write beyond allocated memory regions, potentially corrupting adjacent memory structures.
The operational impact of this vulnerability extends beyond simple denial of service scenarios to potentially enable remote code execution, making it particularly dangerous for systems that process untrusted archive files. An attacker could craft a specially formatted ISO9660 image that, when processed by any application utilizing the vulnerable libarchive library, would trigger memory corruption leading to application crashes or more severe consequences. This vulnerability affects a broad spectrum of software systems including file managers, backup utilities, security scanning tools, and operating system components that rely on libarchive for archive handling. The exploitation potential aligns with ATT&CK technique T1059.007 for execution through archive extraction and T1499.004 for denial of service attacks, demonstrating how this vulnerability can be leveraged in multi-stage attack scenarios.
Mitigation strategies for CVE-2011-1777 require immediate patching of affected libarchive versions to 2.8.6 or later, where the buffer overflow conditions have been addressed through proper input validation and memory bounds checking. System administrators should implement comprehensive vulnerability management processes to identify all software components utilizing libarchive and ensure timely updates across the entire infrastructure. Additionally, deploying network segmentation and access controls can limit the attack surface by restricting which systems can process potentially malicious ISO9660 images. Security monitoring should include detection of unusual archive processing activities and implementation of sandboxed environments for handling untrusted archive files. Organizations should also consider implementing automated patch management solutions to prevent similar vulnerabilities from accumulating in their software supply chains, as this vulnerability demonstrates how memory safety issues in foundational libraries can create widespread security risks across multiple applications and platforms.