CVE-2020-12256
CWE-79Published: May 18, 2020· Updated: Jun 17, 2026
Official Description
rConfig 3.9.4 is vulnerable to reflected XSS. The devicemgmnt.php file improperly validates user input. An attacker can exploit this by crafting arbitrary JavaScript in the deviceId GET parameter to devicemgmnt.php.
Technical Analysis
CVE-2020-12256 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.
From a weakness classification perspective (CWE-79): Cross-site scripting (XSS) vulnerabilities allow attackers to inject malicious scripts into web pages viewed by other users.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
Official Patches & Advisories
All References (2)
Quick Facts
Related CVEs (CWE-79)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2020-12256 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts