Horizon Alert
Summary of the vulnerability and why it matters
This advisory details a path traversal vulnerability affecting Decap CMS, a content management system. The flaw allows unauthorized access to files and directories outside of the intended repository. The primary concern is confirming if this specific technology is in use within our environment and, if so, assessing the potential exposure.
- Unauthorized file access to related directories.
- Confirms risk if the affected content management system is used.
- Assess relevance and exposure for this specific system.
Attack Path
How an attacker could exploit the issue
An attacker could exploit this vulnerability by targeting the Decap CMS through its network exposure. By crafting a request that tricks the system into believing it's accessing a legitimate file within the repository, an attacker can bypass security checks designed to keep them within the intended directory. This could allow them to read, write, or delete files that are outside the designated repository.
- Network access to Decap CMS required.
- Path traversal via sibling directory prefix matching.
- Unauthorized file access and modification.
Live Threat
Current exploitation, exposure, and threat context
This vulnerability could allow an attacker to access and manipulate files outside the intended repository by exploiting how the local proxy handles directory names. When the proxy checks if a request is within the repository, it uses simple string prefix matching without properly validating path separators. This allows an attacker to craft requests that access sibling directories whose names begin with the repository's directory name, leading to unauthorized reading, writing, or deletion of files.
- Repository files could be compromised.
- Sibling directory names could be exploited.
- Unauthorized file access and modification.
Operational Fix
Recommended remediation, mitigation, and detection steps
The real-world ownership of this vulnerability likely falls to teams managing web applications and their associated content management systems, potentially including application owners, platform teams, and security operations. The immediate practical step is to identify all instances of the affected technology, ascertain their exposure and criticality, and then assign an accountable owner to plan remediation.
- Identify affected technology instances.
- Verify exposure and business criticality.
- Plan risk-based remediation.
