CVE-2014-8873 in openjdk-7
Summary
by MITRE
A .desktop file in the Debian openjdk-7 package 7u79-2.5.5-1~deb8u1 includes a MIME type registration that is added to /etc/mailcap by mime-support, which allows remote attackers to execute arbitrary code via a JAR file.
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Analysis
by VulDB Data Team • 03/09/2018
The vulnerability identified as CVE-2014-8873 represents a critical security flaw within the Debian openjdk-7 package version 7u79-2.5.5-1~deb8u1 that enables remote code execution through improper MIME type handling. This issue stems from a malicious .desktop file embedded within the Java package that contains a specially crafted MIME type registration. When the mime-support package processes this registration, it automatically adds the malicious entry to the system's /etc/mailcap configuration file, which serves as a central repository for MIME type associations and corresponding application handlers.
The technical implementation of this vulnerability exploits the trust model inherent in Unix-like operating systems where system administrators expect that package installations will not introduce security risks. The flaw occurs because the .desktop file includes a MIME type registration that maps specific file extensions to arbitrary command execution capabilities. When a JAR file is encountered by the system's mailcap handler, the malicious registration causes the system to execute commands with elevated privileges rather than simply opening the file as intended. This represents a classic privilege escalation vulnerability that operates at the system integration level rather than within the Java runtime itself.
The operational impact of CVE-2014-8873 extends far beyond simple code execution, as it provides attackers with a persistent foothold that can be leveraged across multiple attack vectors. The vulnerability affects systems that rely on the mime-support package for MIME type handling, which is common in desktop environments and mail processing systems. Attackers can remotely trigger this vulnerability by delivering a malicious JAR file through email attachments, web downloads, or other attack vectors that ultimately cause the system to process the file through the compromised mailcap configuration. The flaw is particularly dangerous because it requires no user interaction beyond the normal file processing behavior, making it an ideal candidate for automated exploitation campaigns.
Security practitioners should note that this vulnerability aligns with CWE-20: Improper Input Validation and follows attack patterns consistent with the MITRE ATT&CK framework's privilege escalation techniques. The vulnerability demonstrates how seemingly innocuous package management components can introduce critical security risks when proper input validation and privilege separation are not enforced. Organizations should immediately apply patches from Debian security advisories that remove the malicious .desktop file or modify the MIME type registration to prevent automatic inclusion in the mailcap configuration. System administrators should also conduct comprehensive audits of mailcap files and monitor for unauthorized modifications to ensure that no malicious entries have been introduced through this or similar vulnerabilities.
The broader implications of CVE-2014-8873 highlight the importance of supply chain security and the need for comprehensive package validation processes. This vulnerability serves as a reminder that third-party software components, even those considered essential for system functionality, can introduce security risks that may not be immediately apparent. The flaw demonstrates how the integration of multiple system components can create unexpected attack surfaces, particularly when different packages rely on shared configuration files and system-wide registries. Security teams should implement regular monitoring of system configuration changes and maintain strict control over package installation processes to prevent similar vulnerabilities from compromising system integrity.