CVE-2002-1890 in rhmask
Summary
by MITRE
rhmask 1.0-9 in Red Hat Linux 7.1 allows local users to overwrite arbitrary files via a symlink attack on the mask file.
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Analysis
by VulDB Data Team • 07/05/2024
The vulnerability identified as CVE-2002-1890 resides within the rhmask utility version 1.0-9 distributed with Red Hat Linux 7.1, representing a classic file system security flaw that enables local privilege escalation through symbolic link manipulation. This issue specifically affects the mask file handling mechanism within the rhmask utility, which is designed to manage file access permissions and masking operations within the Red Hat Linux environment. The vulnerability arises from insufficient validation of file paths and symbolic link resolution during the utility's operation, creating a window of opportunity for malicious local users to exploit the system's file handling mechanisms.
The technical flaw manifests when the rhmask utility creates or modifies files without properly verifying the existence of symbolic links in the target path. When a local user can influence the creation of a mask file or manipulate the directory structure, they can establish symbolic links that point to critical system files or configuration resources. This symlink attack vector allows attackers to redirect file operations intended for legitimate mask files to arbitrary locations, enabling them to overwrite or modify files that should remain protected. The vulnerability operates at the operating system level, leveraging the fundamental trust model where the system assumes that file paths represent the intended targets without proper validation of symbolic link chains.
The operational impact of this vulnerability extends beyond simple file overwriting capabilities, as it provides a mechanism for local users to potentially compromise system integrity and security controls. An attacker exploiting this vulnerability can target critical system files such as configuration databases, log files, or even binary executables that are managed by the rhmask utility. The attack requires local system access but does not necessitate elevated privileges, making it particularly dangerous in multi-user environments where users might have legitimate access to the system but should not possess the ability to modify critical system resources. This vulnerability directly relates to CWE-59, which describes improper handling of symbolic links, and can be categorized under ATT&CK technique T1068 for local privilege escalation through file system manipulation.
Mitigation strategies for CVE-2002-1890 involve multiple layers of security controls that address both the immediate vulnerability and broader system security posture. System administrators should immediately apply the vendor patch released for Red Hat Linux 7.1 that corrects the symbolic link handling in the rhmask utility. Additionally, implementing proper file system permissions and access controls can limit the ability of local users to manipulate the directory structure or create symbolic links in critical locations. The principle of least privilege should be enforced, ensuring that only authorized users have the necessary permissions to interact with the rhmask utility or its associated files. Regular system auditing and monitoring of file system changes can help detect potential exploitation attempts, while system hardening practices such as disabling unnecessary utilities and restricting user access to sensitive directories provide additional protective measures against similar vulnerabilities.