Rails Action View - Path Traversal (CVE-2019-5418)

CVE-2019-5418 is a file content disclosure vulnerability in multiple versions of Rails' Action View, where attackers can exploit specially crafted HTTP accept headers to access arbitrary files on the server. This flaw could be leveraged by remote, unauthenticated attackers to read sensitive files, potentially exposing confidential information and aiding in further attacks.

CrowdSec has been tracking this vulnerability and its exploits since 5th of August 2025.

Data from the CrowdSec community indicates that exploitation of CVE-2019-5418 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. In addition, according to the CrowdSec network, attack volume against CVE-2019-5418 has dipped slightly compared to the previous week. Although still commonly targeted, the decline suggests a cooling-off period. Long-term relevance remains, but attention is waning.

Attackers exploit this vulnerability by sending GET requests with a malicious Accept header containing path traversal sequences to disclose sensitive files, but detection is not possible without header inspection.