CVE-1999-1137 in Solaris
Summary
by MITRE
The permissions for the /dev/audio device on Solaris 2.2 and earlier, and SunOS 4.1.x, allow any local user to read from the device, which could be used by an attacker to monitor conversations happening near a machine that has a microphone.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 04/16/2026
The vulnerability described in CVE-1999-1137 represents a critical security flaw in early versions of solaris operating systems that allowed unauthorized local users to access audio input devices. This issue specifically affected Solaris 2.2 and earlier versions as well as SunOS 4.1.x systems where the /dev/audio device permissions were improperly configured. The flaw stems from inadequate access control mechanisms that failed to restrict read access to the audio device to only authorized processes or users. This misconfiguration created a persistent security risk that could be exploited by any local user with access to the system, regardless of their privilege level or authentication status.
The technical nature of this vulnerability can be classified under CWE-264, which addresses permissions, privileges, and access controls. The flaw operates at the operating system level where device files are not properly protected, allowing unauthorized read access to audio input streams. The /dev/audio device in these systems was designed to provide access to audio hardware for legitimate multimedia applications, but the permission model failed to distinguish between authorized and unauthorized access attempts. This represents a fundamental breakdown in the principle of least privilege, where the device file was configured with overly permissive access controls that permitted any local user to capture audio data from the system's microphone.
The operational impact of this vulnerability extends beyond simple privacy concerns to encompass potential information disclosure and surveillance risks. An attacker with local access to a vulnerable system could continuously monitor conversations occurring near the machine, potentially capturing sensitive discussions, passwords, or other confidential information. This capability transforms the system into a covert surveillance tool that could be exploited for espionage or data theft. The vulnerability is particularly concerning because it does not require network connectivity or remote exploitation; the attack can be conducted entirely from within the local system, making detection more difficult. The risk is compounded by the fact that such attacks could occur without any visible system indicators, as the audio capture would be indistinguishable from normal system operations.
Mitigation strategies for this vulnerability must address the core permission issue by implementing proper access controls for device files. System administrators should ensure that the /dev/audio device permissions are properly configured to restrict access to only authorized users or processes through the use of access control lists or proper file ownership settings. The recommended approach involves setting appropriate file permissions that limit read access to specific user groups or processes that legitimately require audio input functionality. Additionally, system administrators should consider implementing additional monitoring and logging mechanisms to detect unauthorized access attempts to audio devices, which aligns with the ATT&CK framework's detection recommendations for privilege escalation and credential access. Regular system audits should verify that device permissions remain properly configured, and security policies should be updated to include specific controls for multimedia device access. This vulnerability serves as a reminder of the importance of proper device file permissions and the need for comprehensive security reviews of system components that handle sensitive data inputs.