CVE-2000-0714 in scheme
Summary
by MITRE
umb-scheme 3.2-11 for Red Hat Linux is installed with world-writeable files.
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Analysis
by VulDB Data Team • 05/27/2018
The vulnerability identified as CVE-2000-0714 relates to the improper permission settings of files within the umb-scheme package version 3.2-11 distributed for Red Hat Linux systems. This issue represents a classic privilege escalation vector through insecure file permissions, where critical system components are configured with world-writable permissions that should typically be restricted to system administrators or specific privileged users only. The umb-scheme package appears to be related to the Universal Mail Box scheme, which is a mail handling system that manages electronic mail routing and processing within Unix-like operating systems. When files within this package are installed with world-writeable permissions, it creates an exploitable condition that allows any user on the system to modify critical components of the mail handling infrastructure.
This vulnerability directly maps to CWE-732: Incorrect Permission Assignment for Critical Resource, which specifically addresses situations where critical system resources are assigned incorrect permissions that allow unauthorized modification by users who should not have such access. The flaw exists at the filesystem permission level rather than in application logic or code execution, making it particularly dangerous as it can be exploited without requiring complex exploitation techniques or code injection. The world-writable permissions essentially remove the security boundary that should protect sensitive system files from modification by unprivileged users, potentially allowing attackers to alter mail routing rules, modify system configurations, or inject malicious code into the mail processing pipeline.
The operational impact of this vulnerability extends beyond simple privilege escalation to potentially compromise the integrity and confidentiality of email communications within the affected system. Attackers with basic user accounts could modify mail handling scripts, redirect email traffic to malicious servers, or insert spam into the mail processing pipeline. This creates a significant risk for organizations relying on the mail infrastructure for business communications, as the compromise could lead to data exfiltration, email spoofing, or disruption of critical communication services. The vulnerability also represents a failure in the system's principle of least privilege, where files that should only be modifiable by system administrators or specific service accounts are accessible for modification by all users, violating fundamental security principles.
The exploitation of this vulnerability aligns with several tactics described in the MITRE ATT&CK framework, particularly those related to privilege escalation and persistence. The technique of leveraging insecure file permissions for privilege escalation falls under the ATT&CK tactic of Privilege Escalation, where adversaries use misconfigurations to gain elevated system privileges. Additionally, this vulnerability could support persistence mechanisms if attackers modify system files to maintain access across system reboots or to ensure continued compromise of the mail infrastructure. Organizations should consider implementing comprehensive file integrity monitoring solutions to detect unauthorized modifications to system files and establish proper permission auditing procedures to identify similar misconfigurations across their infrastructure.
Mitigation strategies for this vulnerability should include immediate remediation through package updates or manual permission correction, ensuring that all system files within the umb-scheme package are set to appropriate permissions that restrict modification to authorized users only. System administrators should implement regular permission audits to identify and correct similar issues across their infrastructure, particularly focusing on critical system packages and services. The implementation of automated security configuration management tools can help prevent such misconfigurations from recurring and ensure that system files maintain appropriate security permissions over time. Organizations should also consider implementing network segmentation and monitoring of mail handling systems to detect potential exploitation attempts and limit the damage that could result from such vulnerabilities.