CVE-2021-21974 is a high-severity vulnerability affecting VMware's ESXi product line. This vulnerability allows a malicious actor residing within the same network segment as ESXi to exploit a heap-overflow condition in the OpenSLP service, resulting in potential remote code execution. The specific versions at risk include ESXi 7.0 prior to ESXi70U1c-17325551, ESXi 6.7 before ESXi670-202102401-SG, and ESXi 6.5 before ESXi650-202102101-SG.
The CVSS score for this vulnerability is 8.8, indicating that it is classified as high severity. The attack vector is adjacent network, which means an attacker must have access to the same local network to exploit this vulnerability. The attack complexity is low, and no privileges or user interaction are required, making it particularly concerning for organizations.
Organizations utilizing affected versions of VMware ESXi should prioritize applying the relevant patches as soon as possible. The risk to organizations includes unauthorized access to sensitive systems and data, which could have serious implications for business operations and compliance.
As of now, there is no public exploit confirmed for this vulnerability, but the potential for remote code execution warrants immediate attention.
Vulnerability Details
The OpenSLP service in VMware ESXi versions 7.0, 6.7, and 6.5 has been identified with a heap-overflow vulnerability. The affected components include VMware Cloud Foundation and ESXi. The vulnerability is classified under CWE-787, indicating a potential heap overflow issue.
Technical Analysis
The root cause of this vulnerability stems from improper handling of memory in the OpenSLP service, which leads to a heap overflow condition. This vulnerability can be exploited through the adjacent network, allowing attackers to send specially crafted packets to the vulnerable service listening on port 427. The attack complexity is low, requiring no privileges or user interactions, thus making it easy for attackers to exploit.
The impacts of a successful exploitation include high confidentiality, integrity, and availability impacts, as attackers may execute arbitrary code with the same privileges as the affected service, leading to further exploitation of the system.
Risk & Impact Analysis
The real-world risk to organizations using affected versions of VMware ESXi is significant. With the ability to execute arbitrary code, attackers could gain unauthorized access to sensitive information and potentially compromise entire systems. Organizations should assess the blast radius of this vulnerability, particularly in environments where ESXi is deployed for critical operations.
Given the high CVSS score of 8.8 and the potential for exploitation, organizations must prioritize addressing this vulnerability in their patch management cycles. The urgency for remediation is high, and timely action will mitigate the risk of potential breaches.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | Yes |
Public PoC | Yes |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The vulnerable versions of VMware ESXi include: 7.0 before ESXi70U1c-17325551, 6.7 before ESXi670-202102401-SG, and 6.5 before ESXi650-202102101-SG. All versions prior to vendor patch are affected.
Mitigation & Remediation
Organizations should apply the latest patches provided by VMware to mitigate this vulnerability. The patches for affected versions are available in the vendor advisory. If an immediate patch cannot be applied, consider implementing network segmentation to restrict access to the OpenSLP service on port 427 and monitor for suspicious activities.
For further security measures, organizations can also consider engaging in penetration testing to assess the overall security posture.
Detection Guidance
To detect potential exploitation attempts, monitor logs for unusual access patterns to port 427. Look for behavioral anomalies that may indicate an ongoing attack, such as unexpected service restarts or high resource usage on ESXi hosts. Network signatures that identify unauthorized access attempts to the OpenSLP service should also be implemented.
AppSecure Threat Intelligence Insight
The long-term significance of CVE-2021-21974 is substantial, as it highlights the risks associated with network-exposed services. Security teams should learn from this incident to improve their defenses against similar vulnerabilities.
Organizations must remain vigilant in monitoring their environments for vulnerabilities and ensure timely updates to their systems. For more information on vulnerability management, consider reviewing our vulnerability management program guide.
Additionally, effective penetration testing methodology can help identify similar vulnerabilities before they can be exploited.
In conclusion, CVE-2021-21974 serves as a reminder of the importance of proactive security measures in maintaining a secure environment.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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