CVE-2015-5278 in QEMU
Summary
by MITRE
The ne2000_receive function in hw/net/ne2000.c in QEMU before 2.4.0.1 allows attackers to cause a denial of service (infinite loop and instance crash) or possibly execute arbitrary code via vectors related to receiving packets.
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Analysis
by VulDB Data Team • 06/15/2022
The vulnerability identified as CVE-2015-5278 represents a critical flaw in the QEMU virtualization platform's network interface implementation, specifically within the ne2000 network card emulation driver. This issue affects QEMU versions prior to 2.4.0.1 and demonstrates a classic buffer handling vulnerability that can be exploited to compromise system stability and potentially achieve arbitrary code execution. The ne2000 network card emulation is widely used in virtual machine configurations, making this vulnerability particularly impactful across various virtualized environments. The vulnerability stems from improper handling of incoming network packets within the ne2000_receive function, which serves as the core packet processing routine for the emulated network interface.
The technical flaw manifests in the ne2000_receive function where insufficient validation occurs during packet processing, allowing malformed or specially crafted network packets to trigger unexpected behavior in the virtual machine's network stack. When an attacker sends carefully constructed packets to a QEMU instance running with the vulnerable ne2000 network card emulation, the function fails to properly validate packet headers or lengths, leading to a condition where the packet processing loop becomes trapped in an infinite loop. This infinite loop occurs because the function does not adequately check for malformed packet structures or handle edge cases that would normally be rejected by legitimate network protocols. The vulnerability can be exploited through various packet types that cause the receive function to continuously process the same packet or to loop through invalid packet structures without proper termination conditions.
The operational impact of this vulnerability extends beyond simple denial of service, as it can potentially lead to arbitrary code execution within the host system running QEMU. When the infinite loop occurs, it consumes excessive CPU resources and can cause the virtual machine instance to crash, effectively creating a denial of service condition that affects all running virtual machines on the host system. The potential for arbitrary code execution arises from the fact that attackers can craft packets that not only trigger the infinite loop but may also cause memory corruption or other exploitable conditions within the QEMU process. This vulnerability is particularly dangerous in multi-tenant environments where multiple virtual machines share the same host resources, as a single compromised virtual machine could potentially affect the entire host system. The issue affects virtualization environments ranging from development and testing platforms to production cloud infrastructure, making it a significant concern for organizations relying on QEMU-based virtualization.
Mitigation strategies for CVE-2015-5278 primarily involve upgrading QEMU to version 2.4.0.1 or later, where the vulnerability has been patched through improved packet validation and proper loop termination conditions in the ne2000_receive function. System administrators should also implement network segmentation and access controls to limit the ability of untrusted networks to send packets to virtual machines, particularly those configured with the vulnerable ne2000 network card emulation. Network monitoring should be enhanced to detect unusual packet patterns that might indicate exploitation attempts, and virtual machine configurations should be reviewed to ensure that unnecessary network interfaces are not exposed to untrusted networks. Additionally, organizations should consider implementing network virtualization security measures such as network intrusion detection systems and packet filtering rules to prevent the transmission of malformed packets to vulnerable QEMU instances. This vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and represents a classic example of how improper input validation can lead to both denial of service and potential privilege escalation scenarios in virtualized environments. The ATT&CK framework categorizes this as a privilege escalation technique through exploitation of virtualization software vulnerabilities, highlighting the broader implications for cloud security and multi-tenant infrastructure protection.