CVE-2013-4393 in systemd
Summary
by MITRE
journald in systemd, when the origin of native messages is set to file, allows local users to cause a denial of service (logging service blocking) via a crafted file descriptor.
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Analysis
by VulDB Data Team • 01/09/2022
The vulnerability identified as CVE-2013-4393 affects journald, which is the logging service component of the systemd system and service manager. This issue specifically manifests when journald is configured to process native messages with their origin set to file, creating a potential vector for local privilege escalation and service disruption. The flaw resides in how journald handles file descriptor inputs from native message sources, allowing malicious actors with local access to manipulate the logging service through crafted file descriptor inputs.
This vulnerability represents a classic case of improper input validation within a system service component, classified under CWE-20 as "Improper Input Validation." The technical implementation flaw occurs when journald processes file descriptors without adequate sanitization or validation of the input data. When native messages are configured to originate from files, the system fails to properly validate or sanitize the file descriptor references, creating a condition where malformed or crafted file descriptors can cause the logging service to malfunction or become unresponsive.
The operational impact of this vulnerability extends beyond simple denial of service, as it can effectively block the entire logging infrastructure of a system running systemd. This disruption can have cascading effects on system monitoring, security auditing, and incident response capabilities since the primary logging service becomes unavailable. Attackers with local access can exploit this weakness to render the system's logging service non-functional, potentially masking their activities while simultaneously disrupting legitimate system operations. The vulnerability is particularly concerning in enterprise environments where centralized logging and monitoring are critical for security operations and compliance requirements.
Mitigation strategies for CVE-2013-4393 should focus on both immediate patching and operational hardening measures. The primary solution involves updating systemd to versions that address this specific vulnerability, as provided by the vendor security advisories. System administrators should also implement proper file descriptor validation mechanisms within their logging configurations and consider implementing monitoring for unusual logging service behavior. Additionally, organizations should follow the principle of least privilege by restricting local access to system services and implementing proper file access controls. The ATT&CK framework categorizes this vulnerability under T1489 as "Service Stop" and T1070.002 as "Indicator Removal on Host," highlighting its potential for both service disruption and evasion techniques that could be used by adversaries to avoid detection while maintaining persistent access to compromised systems.