CVE-2019-3813 in SPICE
Summary
by MITRE
Spice, versions 0.5.2 through 0.14.1, are vulnerable to an out-of-bounds read due to an off-by-one error in memslot_get_virt. This may lead to a denial of service, or, in the worst case, code-execution by unauthenticated attackers.
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Analysis
by VulDB Data Team • 07/04/2023
The spice virtualization component suffers from a critical out-of-bounds read vulnerability that affects versions ranging from 0.5.2 through 0.14.1. This flaw resides within the memslot_get_virt function where an off-by-one error creates a condition that allows memory access beyond allocated boundaries. The vulnerability stems from improper boundary checking during virtual memory slot operations, creating a scenario where an attacker can manipulate memory access patterns to trigger the out-of-bounds read condition. Such memory corruption issues typically arise when developers fail to validate array indices or memory pointer calculations, leading to unauthorized memory access that can compromise system stability and security integrity.
The operational impact of this vulnerability extends beyond simple denial of service conditions to potentially enable remote code execution by unauthenticated attackers. When the off-by-one error occurs in memslot_get_virt, it can cause the system to read memory locations that are not properly allocated or accessible, creating opportunities for attackers to exploit this behavior. The vulnerability's accessibility from unauthenticated sources makes it particularly dangerous in networked environments where spice servers may be exposed to external connections. Attackers can leverage this condition to cause system crashes, data corruption, or potentially execute arbitrary code with the privileges of the affected service, depending on the specific implementation details and memory layout.
This vulnerability aligns with CWE-125, which describes out-of-bounds read conditions in software implementations, and represents a classic example of memory safety issues that can lead to severe security consequences. The ATT&CK framework categorizes this as a memory corruption vulnerability that could be exploited through remote code execution techniques, potentially allowing adversaries to establish persistent access to affected systems. The exploitation of such vulnerabilities often follows attack patterns where initial reconnaissance leads to identification of vulnerable components, followed by crafting of malicious payloads designed to trigger the specific memory access error that causes the out-of-bounds read. Organizations running affected spice versions face significant risk of system compromise, particularly in virtualized environments where spice is commonly used for remote desktop functionality and guest operating system management.
The recommended mitigation strategies include immediate deployment of patched versions of spice components, as well as implementing network segmentation to limit exposure of vulnerable systems to untrusted networks. System administrators should also consider applying additional security controls such as network access controls, intrusion detection systems, and monitoring for unusual memory access patterns or service disruptions that might indicate exploitation attempts. Regular vulnerability assessments and security updates should be implemented to maintain protection against similar memory corruption issues that may arise in other components of the virtualization stack, ensuring comprehensive defense against both known and emerging threats in the virtualization environment.