CVE-2002-1871 in Solaris
Summary
by MITRE
pkgadd in Sun Solaris 2.5.1 through 8 installs files setuid/setgid root if the pkgmap file contains a "?" (question mark) in the (1) mode, (2) owner, or (3) group fields, which allows attackers to elevate privileges.
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Analysis
by VulDB Data Team • 08/27/2019
The vulnerability identified as CVE-2002-1871 represents a critical privilege escalation flaw in the pkgadd utility of Sun Solaris operating systems ranging from version 2.5.1 through 8. This issue stems from improper handling of special characters within the pkgmap file format during package installation processes. The pkgmap file serves as a critical configuration element that defines how package files should be installed, including their permissions, ownership, and group assignments. When the pkgmap file contains a question mark character in any of the mode, owner, or group fields, the pkgadd utility fails to properly validate these entries, creating a security loophole that can be exploited by malicious actors.
The technical mechanism behind this vulnerability operates through the interpretation of the question mark character as a wildcard or placeholder in the pkgmap file parsing logic. When pkgadd encounters a question mark in the mode field, it fails to properly set the file permissions, potentially leaving files with overly permissive settings that include setuid or setgid bits. Similarly, when question marks appear in owner or group fields, the utility does not correctly assign root ownership, leading to files that may be accessible or executable with elevated privileges. This parsing error directly violates security principles by allowing arbitrary file permissions to be set during package installation, bypassing normal access control mechanisms that should prevent unauthorized privilege escalation.
The operational impact of this vulnerability is severe and directly aligns with the MITRE ATT&CK framework's privilege escalation techniques, specifically targeting the T1068 - Exploitation for Privilege Escalation tactic. An attacker who can manipulate package installation processes or gain access to systems where packages are installed can exploit this vulnerability to gain root access. The vulnerability creates a persistent backdoor mechanism where malicious packages can be installed with elevated privileges, allowing attackers to execute arbitrary code with the highest system privileges. This represents a fundamental breakdown in the security model of Solaris systems, as it undermines the integrity of the package management system and the principle of least privilege. The vulnerability affects the core system security infrastructure and can be exploited across multiple attack vectors including compromised package repositories, man-in-the-middle attacks during package downloads, or local privilege escalation scenarios.
Mitigation strategies for this vulnerability must address both immediate remediation and long-term system hardening approaches. The primary fix involves updating to patched versions of Solaris that properly validate pkgmap file entries and reject or properly handle question mark characters in mode, owner, and group fields. System administrators should implement strict package verification processes, including checksum validation and digital signature verification, to prevent installation of malicious packages. Additionally, implementing the principle of least privilege by restricting package installation capabilities to authorized administrators only, combined with regular security auditing of installed packages and their file permissions, provides layered defense against exploitation. Organizations should also consider implementing automated monitoring systems that can detect unauthorized privilege escalation attempts and file permission changes that might indicate exploitation of this vulnerability. The vulnerability's classification under CWE-20 indicates a weakness in input validation, emphasizing the need for robust parsing and validation routines in system utilities. This issue highlights the critical importance of proper input sanitization and validation in security-critical system components, particularly those handling file permissions and system-level operations.