CVE-2001-1277 in makewhatis
Summary
by MITRE
makewhatis in the man package before 1.5i2 allows an attacker in group man to overwrite arbitrary files via a man page whose name contains shell metacharacters.
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Analysis
by VulDB Data Team • 05/30/2018
The vulnerability described in CVE-2001-1277 represents a critical privilege escalation flaw within the man package's makewhatis utility. This issue affects systems where the makewhatis command is executed with elevated privileges and where the man group has access to create or modify man pages. The vulnerability stems from inadequate input validation and sanitization within the makewhatis utility, which processes man page files to generate the whatis database used by the man command. When an attacker belonging to the man group creates a man page with a filename containing shell metacharacters, the utility fails to properly escape or sanitize these characters during processing, leading to potential command injection scenarios.
The technical exploitation of this vulnerability occurs through the manipulation of file naming conventions within the man page directory structure. When makewhatis processes man pages, it relies on shell commands to parse and index the documentation content. The presence of shell metacharacters in filenames allows attackers to inject malicious shell commands that execute with the privileges of the makewhatis process, typically running as root or with elevated permissions. This creates a path for arbitrary file overwrites, where the injected shell commands can target any file accessible to the process, potentially allowing attackers to modify critical system files, install backdoors, or compromise the entire system.
From an operational impact perspective, this vulnerability presents a significant security risk to Unix and Linux systems that rely on the man package for documentation management. The attack vector is particularly dangerous because it requires only membership in the man group, which is often granted to legitimate users for documentation purposes. This makes the vulnerability accessible to users who should not have the ability to modify system files, effectively bypassing normal access controls. The vulnerability can be exploited to create persistent backdoors, modify system binaries, or corrupt system integrity, making it a serious concern for system administrators maintaining documentation systems. According to CWE classification, this represents a CWE-78: Improper Neutralization of Special Elements used in an OS Command, which is a well-documented weakness in command execution handling.
The mitigation strategies for this vulnerability involve several layers of security controls that address both the immediate flaw and broader system protection. The primary remediation is updating the man package to version 1.5i2 or later, which includes proper input sanitization and shell metacharacter handling within the makewhatis utility. System administrators should also implement strict file naming policies that prevent the creation of man pages with special shell characters, and consider removing unnecessary group memberships for users who only require documentation access. Additionally, monitoring for unusual file creation patterns in man page directories can help detect potential exploitation attempts. From an ATT&CK framework perspective, this vulnerability maps to T1068: Exploitation for Privilege Escalation and T1548.001: Abuse of Functionality, as it leverages legitimate system functionality to gain elevated privileges and manipulate system files through command injection techniques. Organizations should also consider implementing file integrity monitoring solutions to detect unauthorized modifications to system files that could result from this vulnerability exploitation.