CVE-2021-1498
Cisco HyperFlex HX Data Platform Command Injection Vulnerability
Description
CVE-2021-1498 is a CRITICAL command injection vulnerability affecting Cisco HyperFlex HX Data Platform, carrying a CVSS 3.1 score of 9.8. The web-based management interface of Cisco HyperFlex HX contains insufficient input validation that allows an unauthenticated, remote attacker to perform command injection attacks, executing arbitrary commands as the tomcat8 user on affected devices. Affected products include Cisco HyperFlex HX Data Platform (< 4.0(2e) and >= 4.5, < 4.5(2a)). This CVE is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog with a remediation deadline of 2021-11-17. With an EPSS score of 0.94206 (99.92th percentile), this vulnerability demonstrates extremely high real-world exploitation probability and demands immediate remediation.
KEV Information
CVSS Score
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HOpen in CalculatorCWEs
Affected Products
| Vendor | Product | Version |
|---|---|---|
| cisco | hyperflex hx data platform | < 4.0\(2e\); >= 4.5, < 4.5\(2a\) |
Multiple CVSS Assessments
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
References
- http://packetstormsecurity.com/files/162976/Cisco-HyperFlex-HX-Data-Platform-Command-Execution.html(Exploit, Third Party Advisory, VDB Entry)
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-hyperflex-rce-TjjNrkpR(Vendor Advisory)
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-1498(US Government Resource)
Weakness Type
CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
CVE-2021-1498 is classified under CWE-78 — OS Command Injection and CWE-77 — Command Injection. Command Injection vulnerabilities occur when software constructs commands using externally-influenced input without proper neutralization of special elements, allowing attackers to inject and execute arbitrary commands on the underlying system. CWE-78 specifically addresses OS command injection, while CWE-77 covers the broader category of command injection including non-OS contexts.
In the context of Cisco HyperFlex HX, this weakness allows unauthenticated attackers to execute commands as the tomcat8 user through the web-based management interface. While the execution context is the tomcat8 service account rather than root (unlike the related CVE-2021-1497), the ability to execute arbitrary commands still provides significant access to the system and can serve as a stepping stone for privilege escalation.
Learn more: CWE-78 — Improper Neutralization of Special Elements used in an OS Command
Impact Analysis
CVE-2021-1498 carries a CVSS 3.1 score of 9.8 (CRITICAL) with Unchanged Scope.
Confidentiality (HIGH): Successful exploitation grants the attacker command execution on the HyperFlex HX system as the tomcat8 user, enabling access to application data, configuration files, service credentials, and potentially sensitive data stored on the hyperconverged infrastructure node.
Integrity (HIGH): Attackers can modify application files, web content, and configurations accessible to the tomcat8 service account. They may also attempt privilege escalation to gain broader system access and install persistent backdoors.
Availability (HIGH): The attacker can disrupt the HyperFlex management services, interfere with platform operations, or potentially cause broader service disruption through manipulation of the web management interface.
Scope Unchanged: The vulnerability's scope is Unchanged (U), meaning impact is technically contained within the HyperFlex HX component, though the practical impact can extend to all workloads managed through the platform.
With an EPSS score of 0.94206 (99.92th percentile), this vulnerability ranks among the most exploited vulnerabilities tracked globally and should be treated as an emergency remediation priority.
Exploit Maturity
CVE-2021-1498 has confirmed active exploitation in the wild and is listed in CISA's Known Exploited Vulnerabilities catalog.
Exploit status: Public exploit code is available for this vulnerability, including exploitation frameworks that automate the attack. The EPSS score of 0.94206 (99.92th percentile) reflects extremely high exploitation activity in the wild.
Ransomware association: As of the latest KEV data, no direct ransomware association has been confirmed for CVE-2021-1498. However, command execution on hyperconverged infrastructure management interfaces provides attackers with a powerful foothold for deploying ransomware across virtualized environments.
Attack surface: The web-based management interface is the primary attack vector. Organizations with HyperFlex management interfaces accessible from untrusted networks face the highest risk. The attack requires no authentication and no user interaction.
KEV deadline: CISA required federal agencies to remediate this vulnerability by 2021-11-17. Given the critical severity and public exploit availability, all organizations should treat this as an immediate priority.
Remediation
- Apply Cisco security patches immediately. Update Cisco HyperFlex HX Data Platform to version 4.0(2e) or later for the 4.0.x branch, or 4.5(2a) or later for the 4.5.x branch. Consult Cisco Security Advisory cisco-sa-hyperflex-rce-TjjNrkpR.
- Identify all HyperFlex HX installations. Inventory all Cisco HyperFlex HX nodes and verify their software versions against the affected ranges.
- Restrict management interface access. Ensure the HyperFlex web-based management interface is not accessible from the internet or untrusted networks. Implement strict access controls on management network segments.
- Monitor for exploitation attempts. Review web server and application logs on HyperFlex nodes for suspicious requests indicative of command injection. Look for unusual processes running as the tomcat8 user.
- Investigate potentially compromised systems. If HyperFlex nodes were running vulnerable versions, conduct forensic analysis. Check for unauthorized file modifications, new processes, unexpected network connections, and privilege escalation attempts from the tomcat8 account.
- Implement defense-in-depth measures. Deploy network-level intrusion detection and prevention systems to detect command injection attempts. Implement application-level firewalls where possible.
- Review and harden service account permissions. Ensure the tomcat8 service account operates with minimal privileges and review any additional access paths that could be leveraged for privilege escalation.
Technical Details
CVE-2021-1498 is a CRITICAL-severity vulnerability in Cisco HyperFlex HX Data Platform that can be exploited remotely over the network. The attack complexity is low, requiring no specialized conditions. No prior authentication or privileges are needed. No user interaction is required, enabling fully automated exploitation.
Technical mechanism: The vulnerability exists in the web-based management interface of Cisco HyperFlex HX due to insufficient input validation. User-supplied input to specific endpoints of the management interface is passed to command execution functions without adequate sanitization. An attacker can send crafted HTTP requests containing command injection payloads that are executed by the system under the tomcat8 service account context.
Execution context: Unlike the related CVE-2021-1497 which executes commands as root, CVE-2021-1498 executes injected commands as the tomcat8 user. While this provides a lower initial privilege level, the tomcat8 account typically has access to application data, configuration files, and network resources that can facilitate further compromise.
Relationship to CVE-2021-1497: Both vulnerabilities affect the same product and are addressed in the same Cisco security advisory. They represent distinct command injection points in the HyperFlex HX management interface with different execution privilege levels.
CVSS 3.1 vector analysis: The vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H reflects a network-accessible attack with low complexity, no privileges required, no user interaction needed, and maximum impact across all three CIA triad dimensions.
Frequently Asked Questions
Is CVE-2021-1498 being actively exploited?
Yes, CVE-2021-1498 is actively exploited in the wild. It is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog with an EPSS score of 0.94206 (99.92th percentile), confirming extremely high exploitation activity. Public exploit code is readily available.
What products are affected by CVE-2021-1498?
Cisco HyperFlex HX Data Platform versions prior to 4.0(2e) and versions 4.5.x prior to 4.5(2a) are affected. Organizations should check all HyperFlex HX nodes in their infrastructure and verify the running software version against these affected ranges.
How do I fix CVE-2021-1498?
Update Cisco HyperFlex HX Data Platform to version 4.0(2e) or later (for 4.0.x) or 4.5(2a) or later (for 4.5.x) as described in Cisco advisory cisco-sa-hyperflex-rce-TjjNrkpR. Restrict management interface access to trusted networks only and investigate for signs of prior compromise.
How severe is CVE-2021-1498?
CVE-2021-1498 is rated CRITICAL with a CVSS 3.1 score of 9.8. It allows unauthenticated remote command execution as the tomcat8 user on HyperFlex HX nodes. While the execution context is a service account rather than root, the combination of no authentication requirement and public exploit availability makes this a critical priority for remediation.
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