Summary
FineReport 9.0 contains a path traversal vulnerability in the unauthenticated
/WebReport/ReportServer design_save_svg operation. An attacker may use
crafted path values to write arbitrary files, potentially placing executable
server-side content and achieving remote code execution when the deployment
permits those files to be processed.
FineReport 9.0 contains a path traversal vulnerability in the unauthenticated
/WebReport/ReportServer design_save_svg operation. An attacker may use
crafted path values to write arbitrary files, potentially placing executable
server-side content and achieving remote code execution when the deployment
permits those files to be processed.
Affected context
The vulnerability occurs in FineReport 9.0 deployments that expose the
/WebReport/ReportServer endpoint and allow unauthenticated requests to reach
the design_save_svg operation. Risk is increased when user-controlled path
values are used to select filesystem locations without canonicalization,
containment checks, or restrictions on writable and executable directories.
The vulnerability occurs in FineReport 9.0 deployments that expose the
/WebReport/ReportServer endpoint and allow unauthenticated requests to reach
the design_save_svg operation. Risk is increased when user-controlled path
values are used to select filesystem locations without canonicalization,
containment checks, or restrictions on writable and executable directories.
Exploit preconditions
- Attack surface: The FineReport WebReport HTTP service and its
design_save_svg operation
- Required access: Network reachability to the endpoint; authentication may
not be required
- Trigger point: Processing a request containing a user-controlled
filePath value and file content
- Why exploitation is possible: The application may interpret traversal
sequences as filesystem navigation and write data outside the intended
directory
- Attack surface: The FineReport WebReport HTTP service and its
design_save_svg operation
- Required access: Network reachability to the endpoint; authentication may
not be required
- Trigger point: Processing a request containing a user-controlled
filePath value and file content
- Why exploitation is possible: The application may interpret traversal
sequences as filesystem navigation and write data outside the intended
directory
Why this happens
The underlying bug is insufficient validation of a user-controlled filesystem
path. When path values are concatenated or resolved without canonicalization,
traversal elements can escape the intended storage directory. This maps to
CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal'). If the resulting location is web-accessible or processed
as executable content, an arbitrary file write can become a code-execution
pathway.
The underlying bug is insufficient validation of a user-controlled filesystem
path. When path values are concatenated or resolved without canonicalization,
traversal elements can escape the intended storage directory. This maps to
CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal'). If the resulting location is web-accessible or processed
as executable content, an arbitrary file write can become a code-execution
pathway.
Potential impact
- An attacker may overwrite or create files outside the intended upload area.
- The application may be forced to serve attacker-controlled content.
- The attacker could achieve remote code execution under the service account.
- Sensitive application data or configuration could be modified or exposed.
- The host and connected systems could face follow-on compromise.
- An attacker may overwrite or create files outside the intended upload area.
- The application may be forced to serve attacker-controlled content.
- The attacker could achieve remote code execution under the service account.
- Sensitive application data or configuration could be modified or exposed.
- The host and connected systems could face follow-on compromise.
General mitigation guidance
Mitigation generally focuses on removing filesystem trust from request
parameters and limiting the consequences of any permitted file writes.
Common defensive patterns include:
- Resolve paths canonically and verify that the result remains within a fixed,
dedicated storage directory.
- Prefer server-generated identifiers and allowlisted file names over
caller-supplied paths.
- Reject traversal syntax, absolute paths, unexpected encodings, and
filesystem separators as a defense-in-depth measure.
- Store user-controlled files outside web roots and executable locations.
- Apply strict permissions so the service account cannot modify application
code or sensitive system paths.
- Require authentication and authorization for file-writing operations where
anonymous access is not essential.
- Use isolated storage and non-executable mounts when feasible.
Mitigation generally focuses on removing filesystem trust from request
parameters and limiting the consequences of any permitted file writes.
Common defensive patterns include:
- Resolve paths canonically and verify that the result remains within a fixed,
dedicated storage directory.
- Prefer server-generated identifiers and allowlisted file names over
caller-supplied paths.
- Reject traversal syntax, absolute paths, unexpected encodings, and
filesystem separators as a defense-in-depth measure.
- Store user-controlled files outside web roots and executable locations.
- Apply strict permissions so the service account cannot modify application
code or sensitive system paths.
- Require authentication and authorization for file-writing operations where
anonymous access is not essential.
- Use isolated storage and non-executable mounts when feasible.
How teams detect issues like this
High-level detection can combine application review, runtime monitoring, and
policy enforcement:
- Use static analysis to identify request parameters flowing into file APIs
without canonicalization and directory-containment checks.
- Review code and configuration for file-writing endpoints that accept paths,
filenames, or upload destinations from clients.
- Monitor web and application logs for traversal indicators, unusual file
creation, unexpected extensions, and requests to design_save_svg.
- Alert on modifications within web roots, application directories, and other
normally immutable locations.
- Enforce policies requiring authentication, path allowlists, and dedicated
non-executable storage for upload functionality.
- Automated code review and software composition tools may help identify
related path-handling patterns.
High-level detection can combine application review, runtime monitoring, and
policy enforcement:
- Use static analysis to identify request parameters flowing into file APIs
without canonicalization and directory-containment checks.
- Review code and configuration for file-writing endpoints that accept paths,
filenames, or upload destinations from clients.
- Monitor web and application logs for traversal indicators, unusual file
creation, unexpected extensions, and requests to design_save_svg.
- Alert on modifications within web roots, application directories, and other
normally immutable locations.
- Enforce policies requiring authentication, path allowlists, and dedicated
non-executable storage for upload functionality.
- Automated code review and software composition tools may help identify
related path-handling patterns.
