Jiangnan Online Judge - Directory Traversal (CVE-2019-17538)

CVE-2019-17538 is a directory traversal vulnerability in Jiangnan Online Judge that allows attackers to read arbitrary files on the server by abusing path traversal in file view requests.

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

Data from the CrowdSec community indicates that exploitation of CVE-2019-17538 is highly selective and intelligence-driven. Threat actors use advanced reconnaissance and carefully choose their targets, often as part of sophisticated campaigns or advanced persistent threat operations. CrowdSec network telemetry also shows that exploitation of CVE-2019-17538 has significantly declined over the past week. Attack volumes are well below the long-term average, suggesting attackers are rapidly losing interest. The vulnerability appears to be falling out of active use across most threat landscapes.

Observed attack attempts target URLs containing /jnoj/web/polygon/problem/viewfile and leverage traversal patterns to gain unauthorized file access.