CVE-2013-2196 in Xen Elf Parser
Summary
by MITRE
Multiple unspecified vulnerabilities in the Elf parser (libelf) in Xen 4.2.x and earlier allow local guest administrators with certain permissions to have an unspecified impact via a crafted kernel, related to "other problems" that are not CVE-2013-2194 or CVE-2013-2195.
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Analysis
by VulDB Data Team • 05/14/2021
The vulnerability identified as CVE-2013-2196 represents a significant security flaw within the Xen hypervisor's libelf component affecting versions 4.2.x and earlier. This issue resides in the ELF parser implementation that Xen utilizes for processing kernel images and other executable files within virtualized environments. The vulnerability specifically targets local guest administrators who possess certain permissions, indicating that the attack vector involves privilege escalation or manipulation within a virtual machine that has already gained some level of access to the host system. The affected libelf implementation demonstrates a critical design flaw that allows malicious actors to exploit the parsing logic through carefully crafted kernel images or executable content, creating a potential pathway for unauthorized system access or data compromise.
The technical nature of this vulnerability stems from improper handling of malformed or specially constructed ELF files within the Xen hypervisor's memory management and kernel loading processes. When a guest administrator with appropriate permissions loads or executes a crafted kernel image, the vulnerable libelf parser fails to properly validate or sanitize the input data, leading to unpredictable behavior that could result in memory corruption, privilege escalation, or arbitrary code execution within the hypervisor environment. This flaw operates at the intersection of virtualization security and kernel security, where the hypervisor's ability to safely process guest-provided kernel images becomes compromised. The vulnerability's classification as "unspecified impact" suggests that the consequences could range from denial of service conditions to complete system compromise, depending on how the malformed input is processed and the specific attack vectors exploited by adversaries.
The operational impact of CVE-2013-2196 extends beyond simple exploitation scenarios to encompass broader virtualization security implications for cloud environments and infrastructure hosting multiple virtual machines. Organizations utilizing Xen hypervisors in production environments face significant risk when running affected versions, as guest administrators could potentially leverage this vulnerability to escape virtual machine isolation boundaries and gain access to other guest instances or the underlying host system. This represents a serious concern for multi-tenant cloud deployments where proper isolation between virtual machines is paramount for security. The vulnerability's relationship to "other problems" not covered by CVE-2013-2194 or CVE-2013-2195 indicates that it represents a distinct but related class of issues within the same codebase, suggesting potential systemic weaknesses in the libelf implementation that require comprehensive review and remediation.
Mitigation strategies for this vulnerability should prioritize immediate patching of Xen hypervisor installations to versions that address the libelf parsing flaws. Organizations must implement comprehensive monitoring of guest administrator activities and kernel loading operations within virtualized environments to detect potential exploitation attempts. The remediation process should include thorough code review of the libelf implementation to identify similar patterns that could lead to additional vulnerabilities, aligning with common weakness enumeration standards such as CWE-129 for improper validation of array indices and CWE-119 for improper restriction of operations within a restricted environment. Security teams should also consider implementing additional virtualization security controls such as kernel lockdown mechanisms and hypervisor hardening measures that align with attack pattern taxonomy frameworks like those described in the mitre attack matrix, particularly focusing on privilege escalation and defense evasion techniques that attackers might employ to exploit such vulnerabilities.