CVE-2021-47794
Published: 16 January 2026
Summary
CVE-2021-47794 is a high-severity OS Command Injection (CWE-78) vulnerability in Zesle Zeslecp. Its CVSS base score is 8.7 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 44.8% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified are NIST 800-53 AC-6 (Least Privilege) and SI-10 (Information Input Validation).
Deeper analysis
CVE-2021-47794 is an authenticated remote code execution vulnerability in ZesleCP 3.1.9, published on 2026-01-16. The issue, tied to CWE-78 (OS Command Injection), has a CVSS v3.1 base score of 8.8 (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H). It arises in the FTP account creation endpoint, where attackers can inject shell payloads into malicious FTP accounts.
Authenticated attackers with low privileges (PR:L) can exploit the vulnerability over the network with low complexity and no user interaction required. By submitting a reverse shell command via the FTP account creation endpoint, they establish a network connection to a listener host under their control, achieving full remote code execution with high impacts on confidentiality, integrity, and availability.
Advisories and proof-of-concept exploits are available, including at https://www.exploit-db.com/exploits/50233 and https://www.vulncheck.com/advisories/zeslecp-remote-code-execution-rce-authenticated. A demonstration video exists at https://www.youtube.com/watch?v=5lTDTEBVq-0, and the vendor site is https://zeslecp.com/.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-3003
Vulnerability details
ZesleCP 3.1.9 contains an authenticated remote code execution vulnerability that allows attackers to create malicious FTP accounts with shell injection payloads. Attackers can exploit the FTP account creation endpoint by injecting a reverse shell command that establishes a network connection…
more
to a specified listening host.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
CVE enables exploitation of a public-facing web application (T1190) via authenticated OS command injection in FTP account creation endpoint, facilitating Unix shell command execution (T1059.004) for RCE such as reverse shells.
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Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly mitigates OS command injection in the FTP account creation endpoint by requiring validation and sanitization of user inputs to prevent shell payload execution.
Requires timely identification, reporting, and correction of flaws like CVE-2021-47794 through patching and integration with configuration management.
Enforces least privilege to restrict low-privilege authenticated users from accessing the vulnerable FTP account creation endpoint, blocking exploitation.