CVE-2013-2930 in Linux
Summary
by MITRE
The perf_trace_event_perm function in kernel/trace/trace_event_perf.c in the Linux kernel before 3.12.2 does not properly restrict access to the perf subsystem, which allows local users to enable function tracing via a crafted application.
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Analysis
by VulDB Data Team • 06/02/2021
The vulnerability described in CVE-2013-2930 resides within the Linux kernel's performance tracing subsystem, specifically in the perf_trace_event_perm function located in kernel/trace/trace_event_perf.c. This flaw represents a significant security weakness that allows local attackers to bypass intended access controls and enable function tracing capabilities through malicious applications. The issue affects Linux kernel versions prior to 3.12.2, making it a persistent concern for systems running older kernel versions. The vulnerability stems from insufficient permission checking mechanisms that should have prevented unauthorized access to performance tracing features.
The technical implementation of this vulnerability involves the perf_trace_event_perm function failing to properly validate access permissions for performance tracing events. When a local user executes a crafted application, the function does not adequately verify whether the requesting process has appropriate privileges to enable function tracing. This misconfiguration allows attackers to leverage the performance subsystem to gain insights into kernel function calls and system behavior that should remain restricted. The flaw operates at the kernel level, making it particularly dangerous as it can be exploited without requiring elevated privileges beyond normal user access. The vulnerability essentially creates an unauthorized backdoor into the kernel's tracing infrastructure.
From an operational perspective, this vulnerability enables local users to perform function tracing that could reveal sensitive system information and potentially aid in further exploitation attempts. Attackers can use the enabled tracing capabilities to gather information about kernel functions, memory layouts, and system behavior patterns that could be valuable for privilege escalation or targeted attacks. The ability to enable function tracing without proper authorization undermines the security model of the Linux kernel, as it allows malicious users to monitor system calls and kernel activities that should remain hidden from regular users. This capability can be particularly dangerous in multi-user environments where privilege separation is critical.
The impact of this vulnerability aligns with CWE-284, which addresses improper access control in software systems. This classification reflects the core issue of insufficient permission checking that allows unauthorized access to restricted kernel functionality. From an ATT&CK framework perspective, this vulnerability maps to techniques involving privilege escalation and defense evasion, as it enables attackers to access kernel tracing capabilities that could be used to hide malicious activities or gather intelligence for further attacks. The vulnerability also relates to technique T1056 which involves input injection and system monitoring, as the crafted application can manipulate the tracing subsystem to achieve unauthorized access.
Mitigation strategies for CVE-2013-2930 primarily focus on kernel updates to versions 3.12.2 or later where the vulnerability has been patched. System administrators should prioritize updating their kernel versions to ensure protection against this specific flaw. Additionally, implementing proper access controls and monitoring for unauthorized tracing activities can help detect potential exploitation attempts. Organizations should also consider disabling unnecessary performance tracing features when not actively required for system monitoring or debugging purposes. The patch for this vulnerability addresses the root cause by implementing proper permission checking in the perf_trace_event_perm function, ensuring that only appropriately authorized processes can enable function tracing within the kernel subsystem.