CVE-2022-31358 in Virtual Environment
Summary
by MITRE • 12/14/2022
A reflected cross-site scripting (XSS) vulnerability in Proxmox Virtual Environment prior to v7.2-3 allows remote attackers to execute arbitrary web scripts or HTML via non-existent endpoints under path /api2/html/.
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Analysis
by VulDB Data Team • 01/12/2023
The vulnerability CVE-2022-31358 represents a critical reflected cross-site scripting flaw within Proxmox Virtual Environment software, specifically affecting versions prior to v7.2-3. This vulnerability resides within the web interface handling of non-existent endpoints under the /api2/html/ path, creating a significant security risk for virtualization environments that rely on this platform. The issue stems from inadequate input validation and output encoding mechanisms within the application's web framework, allowing malicious actors to inject malicious scripts that execute in the context of authenticated users' browsers.
The technical exploitation of this vulnerability occurs when remote attackers craft malicious URLs containing crafted script payloads that are reflected back to users through the web interface. When users navigate to these specifically crafted URLs, the malicious scripts execute within their browser context, potentially leading to session hijacking, credential theft, or unauthorized actions performed on behalf of the victim. The vulnerability specifically affects the API2 HTML interface which serves as the primary web-based management interface for Proxmox Virtual Environment, making it particularly dangerous for administrators who frequently access this interface. This type of vulnerability maps directly to CWE-79, which defines Cross-Site Scripting flaws where insufficient validation of user-supplied data allows attackers to inject malicious scripts into web pages viewed by other users.
The operational impact of this vulnerability extends beyond simple script execution, as it can enable attackers to escalate privileges and gain unauthorized access to virtual machines and containers managed by Proxmox. Attackers can leverage this vulnerability to steal administrator sessions, modify virtual machine configurations, access sensitive data, or even compromise the underlying host systems. The reflected nature of the vulnerability means that attackers can deliver payloads through phishing emails, compromised websites, or social engineering campaigns without requiring persistent access to the target network. This makes the vulnerability particularly dangerous in enterprise environments where administrators may be targeted through spear-phishing attacks that exploit this vulnerability.
Organizations using Proxmox Virtual Environment versions prior to v7.2-3 should immediately apply the vendor-provided patch that addresses this vulnerability through proper input sanitization and output encoding mechanisms. The mitigation strategy should include implementing web application firewalls that can detect and block malicious script payloads, conducting thorough security assessments of the web interface, and monitoring for suspicious access patterns that may indicate exploitation attempts. Security teams should also review and harden the configuration of their Proxmox environments to limit exposure, implement strict access controls, and establish regular patch management processes to prevent similar vulnerabilities from arising in the future. This vulnerability demonstrates the critical importance of maintaining up-to-date security patches in virtualization environments and aligns with ATT&CK technique T1566 for social engineering attacks and T1059 for command and scripting interpreter techniques that attackers may employ when exploiting such vulnerabilities.