CVE-2021-22005

The arbitrary file upload vulnerability present in the Analytics service of vCenter Server allows an attacker with network access to exploit the system by uploading a specially crafted file. This flaw arises from insufficient validation of user-supplied input, enabling the execution of arbitrary code on the server. The vulnerability is particularly concerning due to its high CVSS score of 9.8, indicating a critical risk level. The affected versions of vCenter Server, including 6.5, 6.7, and 7.0, as well as VMware Cloud Foundation, are widely used in enterprise environments, making this vulnerability a significant target for malicious actors.

Attack vectors for this vulnerability primarily involve an attacker gaining access to port 443, which is typically used for secure HTTPS communication. Once access is obtained, the attacker can upload a malicious file that the server may execute, leading to unauthorized code execution. This could be achieved through various means, such as phishing attacks, exploiting other vulnerabilities to gain initial access, or leveraging weak network security practices. Once the attacker has executed code on the server, they could potentially gain control over the entire vCenter Server, manipulate virtual machines, exfiltrate sensitive data, or disrupt services.

The real-world impact of this vulnerability can be severe, particularly for organizations relying on virtualized environments for critical operations. Successful exploitation could lead to unauthorized access to sensitive information, including customer data, intellectual property, and proprietary business processes. Furthermore, the ability to manipulate virtual machines could result in service disruptions, data loss, and significant financial repercussions. The reputational damage from a breach of this nature can also be profound, as customers and partners may lose trust in an organization’s ability to safeguard their data.

To detect and mitigate the risks associated with this vulnerability, organizations should implement a multi-layered security approach. Regularly updating and patching affected products is crucial to close the window of opportunity for attackers. Network segmentation can help limit access to the vCenter Server, ensuring that only authorized personnel can reach port 443. Additionally, organizations should employ intrusion detection systems (IDS) to monitor for unusual activity and potential exploitation attempts. Conducting regular security assessments and penetration testing can also help identify and remediate vulnerabilities before they can be exploited.

In conclusion, the arbitrary file upload vulnerability in the Analytics service of vCenter Server poses a critical threat to organizations utilizing this technology. The potential for unauthorized code execution can lead to severe operational, financial, and reputational consequences. By understanding the technical details of the vulnerability, recognizing possible attack vectors, and implementing robust detection and mitigation strategies, organizations can better protect themselves against this and similar threats. It is imperative for businesses to prioritize cybersecurity measures to safeguard their virtual environments and maintain the integrity of their operations.

CSURFACE threat intelligence has identified a marked escalation in exploitation activity targeting CVE-2021-22005, evidenced by the emergence of multiple new proof-of-concept exploits and the release of a Metasploit module that significantly lowers the technical barrier for attackers. This development has coincided with the vulnerability’s formal inclusion in the CISA KEV catalog, underscoring its criticality and elevating its visibility among defenders. Our telemetry indicates a sharp increase in exploitation attempts, reflecting growing adversary interest and operationalization of this vulnerability. Notably, ransomware groups such as Akira have been linked to campaigns leveraging this flaw, signaling an increased risk of ransomware deployment following successful exploitation. The EPSS score reaching near certainty further validates the heightened likelihood of exploitation in the wild. Collectively, these factors elevate the threat level from theoretical to actively exploited, demanding heightened vigilance from defenders monitoring vCenter Server environments.

Update 2 — July 08, 2026

CSURFACE threat intelligence has identified a marked escalation in detection activity related to CVE-2021-22005, indicating increased adversary engagement with this critical VMware vCenter Server vulnerability. This uptick in telemetry suggests that threat actors, including ransomware groups linked to this exploit, are intensifying their operational use of the arbitrary file upload flaw. Concurrently, new proof-of-concept exploits have surfaced on public repositories, broadening the toolkit available to attackers and lowering the barrier for exploitation. While the EPSS score remains at a near-maximum level, the sustained and growing exploitation attempts underscore a persistent and evolving threat landscape. For defenders, this development signals an elevated risk posture, as the vulnerability continues to be actively targeted with increasing sophistication and frequency, reinforcing the urgency of vigilant monitoring and response within affected environments.