CVE-2025-27553
Published: 23 March 2025
Summary
CVE-2025-27553 is a high-severity Relative Path Traversal (CWE-23) vulnerability in Apache Commons Vfs. Its CVSS base score is 7.5 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 27.7% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-2 (Flaw Remediation).
Threat & Defense at a Glance
Threat & Defense Details
Mitigating Controls (NIST 800-53 r5)AI
Remediating the known flaw by upgrading Apache Commons VFS to version 2.10.0 directly eliminates the path traversal vulnerability in the resolveFile method.
Validating file path inputs to resolveFile prevents encoded traversal sequences like %2E%2E from bypassing the NameScope.DESCENDENT check.
Applying least privilege to the process using Commons VFS limits access to sensitive files outside the intended base directory even if traversal succeeds.
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Remote unauthenticated path traversal in public-facing file API enables initial access via public app exploitation (T1190) and direct unauthorized local file data access (T1005).
NVD Description
Relative Path Traversal vulnerability in Apache Commons VFS before 2.10.0. The FileObject API in Commons VFS has a 'resolveFile' method that takes a 'scope' parameter. Specifying 'NameScope.DESCENDENT' promises that "an exception is thrown if the resolved file is not a…
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descendent of the base file". However, when the path contains encoded ".." characters (for example, "%2E%2E/bar.txt"), it might return file objects that are not a descendent of the base file, without throwing an exception. This issue affects Apache Commons VFS: before 2.10.0. Users are recommended to upgrade to version 2.10.0, which fixes the issue.
Deeper analysisAI
CVE-2025-27553 is a relative path traversal vulnerability in the FileObject API of Apache Commons VFS versions prior to 2.10.0. The 'resolveFile' method accepts a 'scope' parameter, where specifying NameScope.DESCENDENT is intended to throw an exception if the resolved file is not a descendant of the base file. However, when the path includes encoded ".." characters, such as "%2E%2E/bar.txt", the method can return file objects outside the base file's descendant hierarchy without raising an exception, enabling unauthorized file access.
Remote attackers require no privileges or user interaction to exploit this vulnerability over the network with low complexity, as indicated by its CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N). By supplying a malicious path to the resolveFile method with the DESCENDENT scope, an unauthenticated adversary can traverse directory boundaries and access sensitive files outside the intended scope, resulting in high-impact confidentiality violations without affecting integrity or availability.
Apache recommends upgrading to Commons VFS version 2.10.0, which addresses the issue. Official advisories, including those from the Apache mailing lists, OSS-Security, and Debian LTS announcements, confirm the fix and urge affected users to update promptly.
Details
- CWE(s)