CVE-2021-44529
Ivanti Endpoint Manager Cloud Service Appliance (EPM CSA) Code Injection Vulnerability
Description
CVE-2021-44529 is a critical code injection vulnerability in the Ivanti Endpoint Manager Cloud Services Appliance (EPM CSA) that allows unauthenticated remote attackers to execute arbitrary code on the appliance. With a CVSS v3.1 base score of 9.8, this flaw enables network-based exploitation without any authentication or user interaction, though the injected code executes with limited "nobody" permissions. CISA added this vulnerability to the Known Exploited Vulnerabilities (KEV) catalog with a remediation deadline of April 15, 2024, and it has a known ransomware association. The EPSS score of 94.46% at the 100.0th percentile places this at the absolute top of all tracked vulnerabilities in terms of exploitation probability. Affected versions include Ivanti EPM CSA 4.5 and earlier, as well as version 4.6.
KEV Information
CVSS Score
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HOpen in CalculatorAffected Products
| Vendor | Product | Version |
|---|---|---|
| ivanti | endpoint manager cloud services appliance | <= 4.5; 4.6 |
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/166383/Ivanti-Endpoint-Manager-CSA-4.5-4.6-Remote-Code-Execution.html(Exploit, Third Party Advisory, VDB Entry)
- http://packetstormsecurity.com/files/170590/Ivanti-Cloud-Services-Appliance-CSA-Command-Injection.html(Exploit, Third Party Advisory, VDB Entry)
- https://forums.ivanti.com/s/article/SA-2021-12-02(Mitigation, Patch, Vendor Advisory)
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-44529(US Government Resource)
Weakness Type
No specific CWE has been assigned to CVE-2021-44529 by NVD. Based on the vulnerability description, this is a code injection vulnerability (typically classified as CWE-94: Improper Control of Generation of Code). The Ivanti EPM Cloud Services Appliance processes external input in a way that allows an unauthenticated attacker to inject code that is subsequently executed by the application. The code injection executes in the context of the "nobody" user, which has limited system privileges compared to root but still provides a foothold on the appliance. Code injection differs from command injection in that the injected payload is interpreted by the application's own runtime environment rather than the operating system shell, but both ultimately enable arbitrary code execution on the target system.
Impact Analysis
The impact of CVE-2021-44529 is severe across all CIA triad dimensions, compounded by the CSA's role as a gateway between Ivanti's cloud management infrastructure and on-premises endpoint management. Confidentiality is fully compromised because the CSA handles communications between the cloud-based Ivanti management console and managed endpoints. An attacker with code execution on the CSA can intercept management traffic, access device enrollment data, harvest endpoint configuration information, and potentially capture credentials used for endpoint management operations.
Integrity faces maximum impact as the attacker can modify management commands in transit between the cloud console and managed endpoints, inject malicious payloads into software deployment packages, alter configuration policies being pushed to endpoints, and establish persistent backdoors on the CSA that survive service restarts. The CSA's trusted position in the management chain means that manipulated management traffic will be accepted by endpoints without additional verification.
Availability is critically affected because the attacker can disrupt the cloud management communication channel, rendering all cloud-managed endpoints unmanageable, or use the CSA as a pivot point to attack internal network resources. The known ransomware association confirms that ransomware operators are actively exploiting this vulnerability. The EPSS score of 94.46% at the 100.0th percentile means this is at the absolute maximum exploitation probability. The "nobody" user context provides somewhat limited initial access, but post-exploitation privilege escalation on appliance-based systems is frequently achievable through local kernel exploits or misconfigured services, and the management plane access alone provides significant attack capabilities.
Exploit Maturity
CVE-2021-44529 has reached maximum exploit maturity with multiple public exploits, confirmed ransomware campaigns, and sustained mass exploitation. The EPSS score of 94.46% at the 100.0th percentile represents the highest possible exploitation probability rating. CISA's KEV listing with an April 15, 2024 deadline and the known ransomware association underscore the critical and ongoing threat.
Multiple public exploits are available through Packet Storm Security: Ivanti CSA 4.5/4.6 Remote Code Execution and Ivanti CSA Command Injection. Ivanti has published a mitigation and patch advisory at Ivanti SA-2021-12-02. Ivanti products have been heavily targeted by both state-sponsored threat actors and ransomware groups throughout 2023 and 2024, with multiple Ivanti product vulnerabilities appearing in CISA's KEV catalog. This sustained targeting means that threat actors have deep familiarity with Ivanti product architectures, and exploit development for new Ivanti vulnerabilities proceeds rapidly. The unauthenticated remote code execution path with publicly available exploit code ensures that any exposed CSA instance faces near-immediate exploitation.
Remediation
-
Apply the Ivanti security patch immediately for all EPM CSA installations. Consult the Ivanti Security Advisory SA-2021-12-02 for specific patched versions and upgrade instructions. Given the 94.46% EPSS score and known ransomware association, any unpatched CSA should be treated as already compromised.
-
Restrict network access to the CSA appliance as an emergency compensating control. The CSA should not be directly accessible from the internet without network-level access controls. Implement firewall rules that limit inbound connections to the CSA to only authorized IP ranges, and place the appliance behind a reverse proxy or VPN that enforces authentication before traffic reaches the CSA.
-
Conduct forensic analysis of any CSA running affected versions that was exposed to untrusted networks. Review appliance logs for indicators of compromise, check for unauthorized files or processes running as the "nobody" user, examine outbound network connections for command-and-control communication, and verify the integrity of management policies and software packages distributed through the CSA.
-
Audit endpoint configurations and deployments that were managed through the compromised CSA. Verify that no unauthorized software has been deployed, configuration policies have not been tampered with, and endpoint agent integrity is maintained. The CSA's role as a management gateway means that compromise can propagate to all managed endpoints through the trusted management channel.
-
Consider upgrading to the latest CSA version and review the overall Ivanti deployment architecture. Given the repeated targeting of Ivanti products, ensure that all Ivanti components in your environment are on the latest supported versions, implement network segmentation between management infrastructure and production systems, and establish monitoring for anomalous management traffic patterns.
Technical Details
CVE-2021-44529 is a code injection vulnerability in the Ivanti Endpoint Manager Cloud Services Appliance, characterized by the CVSS v3.1 vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. All exploitability metrics are at their most severe values. Attack Vector (AV:N) confirms remote exploitation over the network. Attack Complexity (AC:L) means the exploit works reliably without special conditions. Privileges Required (PR:N) indicates no authentication is needed. User Interaction (UI:N) confirms fully automated exploitation. Scope (S:U) remains unchanged within the CSA appliance context. All impact metrics are High despite the "nobody" user execution context, reflecting the significant damage achievable from the CSA's management position.
The Ivanti EPM Cloud Services Appliance acts as a bridge between Ivanti's cloud-based endpoint management console and the on-premises network where managed endpoints reside. The code injection vulnerability allows an unauthenticated attacker to inject and execute arbitrary code through the CSA's web interface. The injected code runs with the privileges of the "nobody" user, which is a standard Unix unprivileged user account. While "nobody" has limited filesystem and process permissions compared to root, the CSA's application-level access to management databases, endpoint communication channels, and configuration repositories remains available through the application framework. Affected versions include CSA 4.5 and all earlier versions, as well as CSA 4.6. The appliance is typically deployed in the organization's DMZ or perimeter network to facilitate communication between the cloud management plane and internal endpoints, making it inherently internet-accessible and thus directly exposed to exploitation attempts.
Frequently Asked Questions
What is CVE-2021-44529?
CVE-2021-44529 is a critical code injection vulnerability in the Ivanti Endpoint Manager Cloud Services Appliance (EPM CSA) that allows unauthenticated remote attackers to execute arbitrary code on the appliance. With a CVSS score of 9.8 and an EPSS score at the 100th percentile, it is among the most actively exploited vulnerabilities tracked.
What is the Ivanti EPM Cloud Services Appliance?
The CSA is a gateway appliance that connects Ivanti's cloud-based endpoint management platform to on-premises managed devices. It enables organizations to manage endpoints through the cloud while the endpoints remain on internal networks. Compromising the CSA can give attackers access to the management channel for all connected endpoints.
Does the "nobody" user context limit the impact?
While code execution as the "nobody" user has fewer system-level privileges than root, the impact remains critical because the attacker gains access to the CSA's application-level functions, including endpoint management communications and configuration data. Additionally, local privilege escalation from "nobody" to root is frequently achievable on appliance-based systems.
Is this vulnerability associated with ransomware?
Yes, CISA has confirmed a known ransomware association for CVE-2021-44529. Ivanti products have been heavily targeted by ransomware operators who exploit management infrastructure to gain broad access to enterprise networks and deploy ransomware across managed endpoints.
Need Help With Vulnerability Management?
Our security experts can help you prioritize and remediate vulnerabilities effectively.