CVE-2016-6325 in Red Hat
Summary
by MITRE
The Tomcat package on Red Hat Enterprise Linux (RHEL) 5 through 7, JBoss Web Server 3.0, and JBoss EWS 2 uses weak permissions for (1) /etc/sysconfig/tomcat and (2) /etc/tomcat/tomcat.conf, which allows local users to gain privileges by leveraging membership in the tomcat group.
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Analysis
by VulDB Data Team • 09/26/2022
The vulnerability identified as CVE-2016-6325 represents a critical privilege escalation issue affecting multiple versions of the Apache Tomcat web server implementation across various Red Hat Enterprise Linux distributions and JBoss products. This weakness stems from improper file permission configurations that create exploitable pathways for local attackers to elevate their system privileges. The affected systems include RHEL 5 through 7, JBoss Web Server 3.0, and JBoss EWS 2, indicating a widespread impact across different deployment environments and server configurations.
The technical flaw manifests in the configuration files /etc/sysconfig/tomcat and /etc/tomcat/tomcat.conf which are improperly protected with weak permissions that allow members of the tomcat group to modify these critical system files. These configuration files typically contain sensitive parameters including database connection strings, administrative credentials, and system-level settings that control how the Tomcat service operates. When local users possess write access to these files, they can manipulate the service startup parameters and potentially inject malicious code or alter security configurations that govern the application server's behavior.
The operational impact of this vulnerability extends beyond simple privilege escalation as it creates a persistent backdoor mechanism for attackers who gain access to systems with tomcat group membership. Attackers can leverage this weakness to modify the Tomcat service configuration to execute arbitrary code with elevated privileges, potentially leading to complete system compromise. The vulnerability operates under the principle of least privilege violation where the tomcat group should only have read access to these configuration files rather than write permissions that enable modification of critical system parameters. This weakness directly violates security best practices and creates an attack surface that can be exploited by both malicious insiders and external attackers who have gained initial access to systems with tomcat group membership.
The exploitation of this vulnerability aligns with several tactics described in the MITRE ATT&CK framework, particularly those related to privilege escalation and persistence mechanisms. Attackers can use this weakness as part of a broader attack chain where initial access leads to privilege escalation through configuration file manipulation. The vulnerability also relates to CWE-276, which describes improper file permissions, and CWE-732, which covers incorrect permissions for critical resources. Organizations should implement immediate remediation measures including proper file permission settings, regular security audits, and privilege access reviews to prevent exploitation of this weakness and maintain secure system configurations.
Mitigation strategies should focus on implementing proper file permission controls where the configuration files are restricted to root ownership with read-only access for the tomcat group. System administrators should conduct comprehensive security assessments to identify all affected systems and apply appropriate permission changes to prevent unauthorized modification of critical service configuration files. Additionally, organizations should establish automated monitoring systems to detect unauthorized changes to critical system files and implement regular security patching procedures to ensure all systems remain protected against similar vulnerabilities. The remediation process should include verification that the tomcat group has only the minimal required permissions to operate the service without compromising system security.