CVE-2005-0086 in Red Hat
Summary
by MITRE
Heap-based buffer overflow in less in Red Hat Enterprise Linux 3 allows attackers to cause a denial of service (application crash) or possibly execute arbitrary code via a crafted file, as demonstrated using the UTF-8 locale.
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Analysis
by VulDB Data Team • 05/29/2019
The vulnerability identified as CVE-2005-0086 represents a critical heap-based buffer overflow within the less utility on Red Hat Enterprise Linux 3 systems. This flaw exists in the handling of character encoding within the UTF-8 locale environment, specifically when processing crafted input files that contain malformed or excessively long UTF-8 sequences. The vulnerability stems from inadequate bounds checking in the memory allocation routines used by less when interpreting multibyte character sequences, creating a condition where attacker-controlled data can overwrite adjacent heap memory regions. This type of vulnerability falls under the CWE-121 heap-based buffer overflow category, which is classified as a common weakness in software security implementations and is particularly dangerous due to its potential for arbitrary code execution.
The technical exploitation of this vulnerability occurs when an attacker constructs a specially crafted file that contains UTF-8 encoded sequences designed to trigger the buffer overflow condition. When the less utility processes this file under UTF-8 locale settings, the flawed memory management causes the application to write beyond the allocated heap buffer boundaries. This overflow can corrupt adjacent memory structures including stack canaries, return addresses, or other critical program data, leading to unpredictable behavior. The vulnerability is particularly concerning because it can be exploited to achieve arbitrary code execution, as the corrupted memory can be manipulated to redirect program execution flow, or it can simply cause a denial of service through application crashes that prevent legitimate users from accessing the system resources.
From an operational perspective, this vulnerability presents significant risks to enterprise environments running Red Hat Enterprise Linux 3 systems, particularly in scenarios where users might encounter untrusted files through email attachments, file sharing systems, or web-based content. The impact extends beyond simple service disruption to potentially allow full system compromise, as successful exploitation could enable attackers to execute malicious code with the privileges of the user running the less utility. The attack surface is broad since less is a commonly used command-line utility for viewing text files, making it accessible through various attack vectors including web applications that may display file contents or email clients that process text documents. This vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter, as exploitation could occur through command-line interfaces where less is invoked.
Mitigation strategies for CVE-2005-0086 should prioritize immediate patching of affected systems with the vendor-provided security updates for Red Hat Enterprise Linux 3. Organizations should also implement restrictive file access controls and sanitize all input files before processing them through less or similar text viewing utilities. Network segmentation and privilege separation can help limit the potential impact of successful exploitation by preventing attackers from gaining access to critical system resources. Additionally, system administrators should monitor for unusual process behavior and implement intrusion detection systems that can identify attempts to exploit buffer overflow vulnerabilities through anomalous memory access patterns or unexpected application crashes. The vulnerability demonstrates the importance of proper input validation and memory management practices in preventing heap-based buffer overflows, which aligns with security best practices outlined in the OWASP Top Ten and NIST cybersecurity frameworks for preventing common software vulnerabilities.