The vSphere Client (HTML5) contains an SSRF (Server Side Request Forgery) vulnerability due to improper validation of URLs in a vCenter Server plugin. A malicious actor with network access to port 443 may exploit this issue by sending a POST request to the vCenter Server plugin leading to information disclosure. This affects: VMware vCenter Server (7.x before 7.0 U1c, 6.7 before 6.7 U3l, and 6.5 before 6.5 U3n) and VMware Cloud Foundation (4.x before 4.2 and 3.x before 3.10.1.2).
With a CVSS score of 5.3, this vulnerability is classified as medium severity. Organizations should understand the implications of this vulnerability as it allows unauthorized access to sensitive information, which can be detrimental to their operations.
The exploitation status has been confirmed as active, with the vulnerability being included in the Known Exploited Vulnerabilities (KEV) catalog. Organizations are advised to prioritize remediation efforts to minimize risk exposure.
Organizations should prioritize patching immediately to mitigate the risk associated with this vulnerability.
In light of the recent trends in cyber attacks, understanding and responding to vulnerabilities such as CVE-2021-21973 is crucial for maintaining security posture in any organization reliant on VMware products.
Vulnerability Details
The SSRF vulnerability allows attackers to send unauthorized requests to internal servers, which may lead to information disclosure. The CVE-2021-21973 vulnerability specifically affects VMware vCenter Server and VMware Cloud Foundation versions that have not been patched.
This vulnerability has been assigned CWE-918, which pertains to Server-Side Request Forgery. The issue stems from a lack of proper validation of URLs that can be requested by the vCenter Server plugin.
The vulnerability was published on February 24, 2021, and has since been analyzed thoroughly, receiving a CVSS score of 5.3, which indicates that it poses a medium risk to organizations.
Technical Analysis
The root cause of this vulnerability lies in the improper validation of URLs within the vCenter Server plugin. The attack vector for this vulnerability is network-based, allowing attackers to exploit it remotely without any user interaction.
The attack complexity is considered low, as attackers do not require any privileges to exploit this vulnerability. The confidentiality impact is rated as low, meaning that sensitive information may be disclosed, but integrity and availability are not affected.
Risk & Impact Analysis
Risk to organizations includes potential unauthorized access to sensitive information, which could lead to further attacks or data breaches. The blast radius of this vulnerability is significant, as it affects multiple versions of popular VMware products, making it critical for organizations to address this vulnerability promptly.
Organizations should address this vulnerability in their priority patch cycle. The urgency is heightened due to its active exploitation status, which reflects the increasing number of cyber threats targeting such vulnerabilities.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | Yes |
Public PoC | Yes |
Actively Exploited | Yes |
Ransomware Use | No |
Affected Versions
This vulnerability affects VMware vCenter Server versions 7.x before 7.0 U1c, 6.7 before 6.7 U3l, and 6.5 before 6.5 U3n, as well as VMware Cloud Foundation versions 4.x before 4.2 and 3.x before 3.10.1.2.
Mitigation & Remediation
To remediate this vulnerability, organizations should apply the patches provided by VMware for the affected versions. For further guidance, organizations can refer to the vendor's advisory for patching instructions.
Organizations may also consider implementing network controls and monitoring configurations to limit exposure until the patches are applied. For security assessments, organizations can utilize penetration testing to identify and fix similar vulnerabilities.
Detection Guidance
Security teams should monitor logs for unusual requests to the vCenter Server plugin, especially POST requests that seem to have unusual URL patterns. Behavioral anomalies in network traffic could also indicate exploitation attempts.
AppSecure Threat Intelligence Insight
The long-term significance of this vulnerability is notable as it highlights the ongoing threat of SSRF vulnerabilities in widely-used applications. Organizations must remain vigilant in patching and monitoring their systems to defend against similar future vulnerabilities.
This vulnerability represents a trend where attackers exploit SSRF vulnerabilities to gain access to sensitive information. Security teams should prioritize the implementation of secure coding practices to minimize such risks.
For more information on best practices in penetration testing and vulnerability management, organizations can refer to resources such as the vulnerability management program design guide.
Moreover, understanding the implications of this vulnerability can inform security strategies, ensuring that organizations are better prepared to handle future threats.
Known Exploitation Timeline
This vulnerability was added to the KEV catalog on March 7, 2022, emphasizing its relevance and urgency in the current threat landscape.
EPSS Risk Context
With an EPSS score of 0.903, this vulnerability sits at the 99.6th percentile, indicating a high likelihood of exploitation in the wild. Organizations should take this score seriously as part of their risk assessment.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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