DrayTek VigorConnect - LFI (CVE-2021-20124)

CVE-2021-20124 is a vulnerability present in DrayTek VigorConnect that allows unauthenticated attackers to perform local file inclusion through the WebServlet endpoint, which could enable the unauthorized download of arbitrary files with elevated privileges.

CrowdSec has been tracking this vulnerability and its exploits since 10th of March 2025.

According to CrowdSec data, while opportunistic exploitation dominates, a portion of threat actors trying to exploit CVE-2021-20124 apply basic targeting methods such as port or service detection. This indicates emerging patterns of selective targeting. Additionally, according to week-over-week analysis by CrowdSec, exploitation of CVE-2021-20124 is surging. Attack volumes are spiking well above historical norms, indicating widespread and escalating interest from threat actors. CVE-2021-20124 is currently experiencing high visibility and active exploitation across the internet.

Exploitation attempts typically involve requests to URLs containing both acsserver/webservlet and act=getmapimg_acs2.