CVE-2018-20724 in Cacti
Summary
by MITRE
A cross-site scripting (XSS) vulnerability exists in pollers.php in Cacti before 1.2.0 due to lack of escaping of unintended characters in the Website Hostname for Data Collectors.
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Analysis
by VulDB Data Team • 08/27/2025
The vulnerability identified as CVE-2018-20724 represents a critical cross-site scripting flaw within the Cacti network monitoring platform, specifically affecting versions prior to 1.2.0. This vulnerability resides in the pollers.php component which handles data collection processes for network monitoring. The issue stems from insufficient input validation and output sanitization mechanisms that fail to properly escape or filter user-supplied data when processing Website Hostname parameters for Data Collectors. The flaw allows malicious actors to inject arbitrary web scripts into the application's response, potentially compromising the security of users who interact with the affected system.
The technical exploitation of this vulnerability occurs when an attacker crafts malicious input containing script code within the Website Hostname field used for Data Collectors configuration. When the pollers.php script processes this input without proper sanitization, the malicious code gets executed within the context of other users' browsers who view the affected pages. This creates a persistent XSS vector that can be leveraged for session hijacking, credential theft, or redirection to malicious sites. The vulnerability maps directly to CWE-79, which defines Cross-Site Scripting as a weakness where untrusted data is embedded into web pages viewed by other users without proper validation or escaping.
From an operational perspective, this vulnerability poses significant risks to network monitoring environments that rely on Cacti for system administration. Attackers could exploit this flaw to gain unauthorized access to monitoring data, manipulate network statistics, or establish persistent access points within the network infrastructure. The impact extends beyond simple data theft since compromised monitoring systems can provide attackers with insights into network topology, device configurations, and operational patterns. This vulnerability particularly affects organizations that use Cacti for critical infrastructure monitoring where unauthorized access to monitoring data could lead to severe operational disruptions or security breaches.
The mitigation strategy for CVE-2018-20724 requires immediate implementation of the official patch released by the Cacti development team for versions 1.2.0 and later. Organizations should also implement additional defensive measures including input validation at multiple layers, output encoding for all user-supplied data, and regular security assessments of web applications. Network administrators should consider implementing web application firewalls to detect and block potential exploitation attempts. The vulnerability aligns with ATT&CK technique T1566 which covers social engineering attacks through malicious web content, and T1071 which addresses application layer protocols including web services that may be exploited for data exfiltration. Organizations should also conduct thorough testing of the patched version to ensure that the XSS mitigation does not introduce regressions in legitimate functionality while maintaining the integrity of the monitoring infrastructure.