CVE-2021-47853: 
Echo vulnerability analysis and mitigation

CVE-2021-47853 is a rejected CVE that was originally described as a remote command execution vulnerability in phpPgAdmin 7.13.0, allowing authenticated attackers to execute arbitrary OS commands via SQL query manipulation using PostgreSQL's COPY FROM PROGRAM command. The CVE was initially submitted by VulnCheck on January 21, 2026, and subsequently rejected by VulnCheck (the CVE Numbering Authority) on February 1, 2026. Because this CVE has been officially withdrawn, no authoritative CVSS score is assigned by NVD; VulnCheck had provisionally assigned a CVSS v3.1 score of 8.8 (High) and a CVSS v4.0 score of 8.6 (High) prior to rejection (Red Hat CVE).

Prior to its rejection, the vulnerability was classified as CWE-78 (Improper Neutralization of Special Elements used in an OS Command — OS Command Injection). The described attack vector involved an authenticated attacker creating a custom table in phpPgAdmin, uploading a malicious .txt file, and then leveraging PostgreSQL's COPY FROM PROGRAM SQL command to execute arbitrary operating system commands with the privileges of the phpPgAdmin application process. Exploitation required valid credentials (low-privilege authenticated access per the original CVSS v3.1 vector) and network access, but no user interaction. A related exploit was referenced on Exploit-DB (exploit ID 49736), though this reference was removed when the CVE was rejected (Red Hat CVE).

As originally described before rejection, successful exploitation would have allowed an authenticated attacker to execute arbitrary OS commands with the privileges of the phpPgAdmin web application, potentially leading to full system compromise, unauthorized access to sensitive data, data modification or deletion, and service disruption. The scope was limited to the host running phpPgAdmin, with no lateral movement implied by the original CVSS scoring. Because the CVE has been officially rejected, these impacts are not confirmed as a distinct, novel vulnerability.

CVE-2021-47853 has been rejected by its CVE Numbering Authority (VulnCheck), meaning it is not recognized as a valid, distinct vulnerability. Prior to rejection, VulnCheck referenced Exploit-DB exploit 49736 and a VulnCheck advisory, but these references were removed upon rejection. There is no confirmed evidence of in-the-wild exploitation, no CISA KEV listing, and the EPSS score is approximately 0.0026 (very low). The underlying technique — abusing PostgreSQL's COPY FROM PROGRAM in phpPgAdmin — is a known attack pattern, but it is not attributed to a unique vulnerability in phpPgAdmin 7.13.0 as a separate CVE (Red Hat CVE).

Because CVE-2021-47853 has been officially rejected, there is no vendor patch associated with this specific CVE. Organizations using phpPgAdmin should nonetheless follow general hardening practices: restrict phpPgAdmin access to trusted networks only, enforce strong authentication, and limit database user privileges to prevent use of dangerous PostgreSQL commands such as COPY FROM PROGRAM. If phpPgAdmin is not actively required, it should be disabled or removed. Monitor for suspicious SQL query patterns and unexpected file uploads within the application (Red Hat CVE).