CVE-2019-3687 in Linux Enterprise Server
Summary
by MITRE
The permission package in SUSE Linux Enterprise Server allowed all local users to run dumpcap in the "easy" permission profile and sniff network traffic. This issue affects: SUSE Linux Enterprise Server permissions versions starting from 85c83fef7e017f8ab7f8602d3163786d57344439 to 081d081dcfaf61710bda34bc21c80c66276119aa.
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Analysis
by VulDB Data Team • 03/26/2024
The vulnerability described in CVE-2019-3687 represents a critical privilege escalation and network monitoring flaw within SUSE Linux Enterprise Server permission packages. This issue stems from an overly permissive configuration that allows all local users to execute dumpcap with elevated capabilities through the "easy" permission profile. The dumpcap utility, which is part of the Wireshark network protocol analyzer suite, typically requires specific permissions to capture network packets at the system level. However, in this vulnerable state, local users could bypass normal access controls and gain the ability to monitor all network traffic passing through the system, effectively creating a backdoor for passive network reconnaissance and potential data exfiltration.
The technical implementation of this vulnerability involves the permission package's configuration management where the "easy" profile was incorrectly designed to grant broad network monitoring capabilities without proper access controls. This flaw specifically affects SUSE Linux Enterprise Server versions within a defined commit range from 85c83fef7e017f8ab7f8602d3163786d57344439 to 081d081dcfaf61710bda34bc21c80c66276119aa, indicating a targeted codebase issue rather than a broader system-wide problem. The vulnerability manifests as a lack of proper privilege separation and security context management, allowing unauthorized local users to execute network monitoring tools with capabilities typically reserved for system administrators or specialized network monitoring services.
The operational impact of this vulnerability extends beyond simple network sniffing capabilities, as it enables persistent surveillance of network communications and potentially exposes sensitive data in transit. An attacker with local access could monitor all network traffic, including encrypted communications that might be subject to man-in-the-middle attacks or credential harvesting. This vulnerability directly violates the principle of least privilege and creates a persistent threat vector that could be exploited to gather intelligence about network topology, identify vulnerable services, or intercept sensitive information. The implications are particularly severe in enterprise environments where SUSE Linux Enterprise Server serves as a critical infrastructure component, as it could allow attackers to gain visibility into internal network communications and potentially escalate their access to other system components.
Security mitigations for this vulnerability should focus on implementing proper permission controls and privilege separation within the SUSE Linux Enterprise Server permission package. System administrators should immediately update to patched versions of the permission package that properly restrict dumpcap execution to authorized users only. The recommended approach includes reviewing and tightening the "easy" permission profile configuration to remove unnecessary network monitoring capabilities, implementing mandatory access controls, and ensuring that network monitoring tools require explicit administrative privileges. This vulnerability aligns with CWE-276, which addresses improper permissions and access control issues, and maps to ATT&CK technique T1046 for network service scanning and T1074 for data staging through network monitoring capabilities. Organizations should also implement network monitoring of privileged user activities and establish regular security audits to detect and prevent similar permission misconfigurations in other system components.