CVE-1999-1080 in Solaris
Summary
by MITRE
rmmount in SunOS 5.7 may mount file systems without the nosuid flag set, contrary to the documentation and its use in previous versions of SunOS, which could allow local users with physical access to gain root privileges by mounting a floppy or CD-ROM that contains a setuid program and running volcheck, when the file systems do not have the nosuid option specified in rmmount.conf.
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Analysis
by VulDB Data Team • 04/16/2026
The vulnerability described in CVE-1999-1080 represents a critical security flaw in SunOS 5.7's rmmount utility that directly undermines the operating system's privilege separation mechanisms. This issue manifests when the rmmount utility fails to properly enforce the nosuid mount option, creating a pathway for privilege escalation attacks. The flaw exists specifically in how the system handles removable media mounting operations, particularly when dealing with floppy disks and CD-ROMs that may contain setuid programs. The vulnerability stems from a deviation from documented behavior and previous SunOS versions where the nosuid flag was consistently applied, making this a regression in security controls that had been established in prior releases.
The technical implementation of this vulnerability occurs within the rmmount utility's file system mounting process where it neglects to apply the nosuid flag during mount operations. This failure allows local users with physical access to removable media to mount filesystems without proper security restrictions that would normally prevent the execution of setuid programs. When a user mounts a filesystem containing a setuid binary and subsequently runs volcheck, which is designed to verify mounted volumes, the system executes the setuid program with elevated privileges. This represents a direct violation of Unix security principles where setuid programs should not be executable from mounted filesystems without explicit permission. The flaw operates at the kernel level through the mount system call interface and directly impacts the security model by bypassing the intended protection mechanisms.
The operational impact of this vulnerability is significant as it provides local attackers with a straightforward path to root privilege escalation without requiring network access or complex exploitation techniques. The attack vector requires only physical access to the system and the ability to insert removable media containing malicious setuid programs. This makes the vulnerability particularly dangerous in environments where physical security is compromised or where users have unattended access to systems. The vulnerability affects systems running SunOS 5.7 where the rmmount utility does not properly enforce the nosuid option in rmmount.conf, potentially affecting a wide range of enterprise and server deployments that rely on this mounting functionality. The impact extends beyond simple privilege escalation to potentially compromise the entire system integrity, as successful exploitation allows attackers to execute arbitrary code with root privileges.
The mitigation strategies for this vulnerability involve multiple layers of defense that address both the immediate security issue and broader system hardening. The primary recommendation is to modify the rmmount.conf configuration file to explicitly enforce the nosuid option for all removable media mounts, ensuring that the system behavior aligns with documented security requirements. System administrators should also implement proper physical security controls to prevent unauthorized access to systems, as the vulnerability specifically requires physical access to exploit. Additionally, regular security audits should verify that mount options are properly configured and that the rmmount utility behaves consistently with documented security policies. This vulnerability aligns with CWE-276, which addresses improper privilege management, and represents a specific case of inadequate access control where security mechanisms fail to prevent unauthorized privilege escalation. The ATT&CK framework categorizes this under privilege escalation techniques where adversaries leverage system configuration flaws to gain elevated privileges. Organizations should also consider implementing automated monitoring solutions to detect unauthorized mount operations and ensure compliance with security policies. The vulnerability demonstrates the importance of maintaining consistent security behavior across system versions and highlights the need for comprehensive testing of security controls during system updates and patches.