{"id":21834,"date":"2025-04-12T02:55:42","date_gmt":"2025-04-12T02:55:42","guid":{"rendered":""},"modified":"2025-09-16T07:09:02","modified_gmt":"2025-09-16T13:09:02","slug":"cve-2021-47667-critical-os-command-injection-vulnerability-in-zendto","status":"publish","type":"post","link":"https:\/\/www.ameeba.com\/blog\/cve-2021-47667-critical-os-command-injection-vulnerability-in-zendto\/","title":{"rendered":"CVE-2021-47667: Critical OS Command Injection Vulnerability in ZendTo<\/strong>"},"content":{"rendered":"

Overview<\/strong><\/p>\n

A high severity vulnerability, identified as CVE-2021-47667, has been discovered in ZendTo versions 5.24-3 through 6.x before 6.10-7. This vulnerability, an OS command injection, could allow unauthorized remote attackers to execute arbitrary commands on the affected system, potentially leading to system compromise or data leakage. This issue requires immediate attention and mitigation, particularly for businesses and organizations utilizing ZendTo for file sharing and transfer, as the vulnerability could be exploited<\/a> to gain unauthorized access to sensitive information.<\/p>\n

Vulnerability Summary<\/strong><\/p>\n

CVE ID: CVE-2021-47667
\nSeverity: Critical (CVSS: 10.0)
\nAttack Vector: Network
\nPrivileges Required: None
\nUser Interaction: None
\nImpact: Potential system<\/a> compromise or data leakage<\/p>\n

Affected Products<\/strong><\/p>\n

Product | Affected Versions<\/p>\n

ZendTo | 5.24-3 through 6.x before 6.10-7<\/p>\n

How the Exploit Works<\/strong><\/p>\n

This vulnerability exists due to improper<\/a> sanitization of the ‘tmp_name’ parameter in the lib\/NSSDropoff.php script when a file is dropped off via a POST\/dropoff request. This allows an attacker to inject shell meta-characters, which are interpreted and executed by the system<\/a>. As a result, an attacker can execute arbitrary<\/a> system commands, compromising the system or potentially leading to data leakage.<\/p>\n

Conceptual Example Code<\/strong><\/p>\n

Here is a conceptual example of how this vulnerability might be exploited<\/a>. In this case, the attacker sends a malicious POST request<\/a> to the \/dropoff endpoint with shell meta-characters in the ‘tmp_name’ parameter:<\/p>\n

POST \/dropoff HTTP\/1.1\nHost: target.example.com\nContent-Type: multipart\/form-data\n--boundary\nContent-Disposition: form-data; name=\"tmp_name\"\n; rm -rf \/; #\n--boundary--<\/code><\/pre>\n
In the above example, the attacker attempts to delete all files<\/a> in the system root directory. This is just a conceptual example, the actual payload would depend on the attacker’s intent and the specific system configuration<\/a>.<\/p>\n
Mitigation and Patch Information<\/strong><\/p>\n
The vendor has released a patch for this vulnerability in version<\/a> 6.10-7. It is highly recommended to install this patch as soon as possible. If immediate patching is not possible, temporary mitigation measures include the use of a Web Application Firewall (WAF) or Intrusion Detection System (IDS) to detect and block attempts to exploit this vulnerability.<\/p>\n","protected":false},"excerpt":{"rendered":"
Overview A high severity vulnerability, identified as CVE-2021-47667, has been discovered in ZendTo versions 5.24-3 through 6.x before 6.10-7. This vulnerability, an OS command injection, could allow unauthorized remote attackers to execute arbitrary commands on the affected system, potentially leading to system compromise or data leakage. This issue requires immediate attention and mitigation, particularly for […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"footnotes":""},"categories":[1],"tags":[],"vendor":[],"product":[],"attack_vector":[78],"asset_type":[],"severity":[],"exploit_status":[],"class_list":["post-21834","post","type-post","status-publish","format-standard","hentry","category-uncategorized","attack_vector-injection"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t