CVE-2014-0142 in QEMU
Summary
by MITRE
QEMU, possibly before 2.0.0, allows local users to cause a denial of service (divide-by-zero error and crash) via a zero value in the (1) tracks field to the seek_to_sector function in block/parallels.c or (2) extent_size field in the bochs function in block/bochs.c.
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Analysis
by VulDB Data Team • 06/16/2021
The vulnerability identified as CVE-2014-0142 affects QEMU virtualization software, specifically targeting versions prior to 2.0.0. This issue represents a critical denial of service flaw that can be exploited by local attackers to crash the virtualization environment through carefully crafted input values. The vulnerability manifests in two distinct code paths within QEMU's block device handling subsystem, demonstrating the complexity of virtualization security concerns and the potential for seemingly minor input validation issues to result in system-wide crashes.
The technical flaw exists in the block/parallels.c and block/bochs.c source files where input validation is insufficient for handling specific field values. In the parallels.c file, the seek_to_sector function fails to properly validate the tracks field, while in bochs.c, the bochs function does not adequately check the extent_size field. When these fields receive zero values, the code path leads to a divide-by-zero error that crashes the QEMU process. This type of vulnerability falls under CWE-369, Divide by Zero, which is classified as a common weakness in software security where arithmetic operations attempt to divide by zero, leading to program termination.
The operational impact of this vulnerability extends beyond simple service disruption as it can be exploited by local users to cause complete system instability within virtualized environments. In enterprise settings where QEMU serves as a core component for virtual machine management, such a flaw could be leveraged to disrupt critical virtualization infrastructure, potentially affecting multiple virtual machines running on the same host system. The vulnerability's local nature means that any user with access to the system can exploit it, making it particularly dangerous in multi-tenant virtualization environments where privilege separation may be insufficient.
From a threat modeling perspective, this vulnerability aligns with ATT&CK technique T1499.001 which involves network denial of service attacks, though in this case the attack vector is local rather than network-based. The flaw demonstrates how virtualization platforms can be compromised through input validation failures in storage handling components, highlighting the importance of robust input sanitization in hypervisor code. Security practitioners should note that this issue represents a classic example of how seemingly benign input values can trigger catastrophic failures in complex software systems, particularly in virtualization environments where multiple components interact in sophisticated ways.
The recommended mitigations for CVE-2014-0142 include immediate upgrade to QEMU version 2.0.0 or later where the vulnerability has been patched. Organizations should also implement comprehensive input validation measures in their virtualization environments and consider deploying additional monitoring to detect anomalous behavior patterns that might indicate exploitation attempts. System administrators should review their virtualization infrastructure for similar input validation issues and ensure that all storage-related components properly validate field values to prevent arithmetic errors that could lead to system crashes. The vulnerability serves as a reminder of the critical importance of proper input validation in security-sensitive code, particularly in hypervisor and virtualization software where system stability is paramount.