Summary
Apache Camel's Mina SFTP remote-file consumer can construct remote paths from directory-listing names without normalizing them or verifying that they remain inside the configured polling directory. A malicious or compromised server, or an attacker able to alter listing data in transit, may therefore cause Camel to read, delete, or rename files outside the intended directory using the endpoint's credentials.
Apache Camel's Mina SFTP remote-file consumer can construct remote paths from directory-listing names without normalizing them or verifying that they remain inside the configured polling directory. A malicious or compromised server, or an attacker able to alter listing data in transit, may therefore cause Camel to read, delete, or rename files outside the intended directory using the endpoint's credentials.
Affected context
The issue occurs in Apache Camel deployments using the Mina SFTP component's remote-file consumer within the affected release streams. It becomes relevant when a remote directory listing contains a name with path components rather than a single file-name segment, and when Camel processes that name for retrieval, deletion, or renaming. Retrieval is part of normal consumer behavior, while deletion and renaming depend on endpoint disposition or read-lock configuration.
The issue occurs in Apache Camel deployments using the Mina SFTP component's remote-file consumer within the affected release streams. It becomes relevant when a remote directory listing contains a name with path components rather than a single file-name segment, and when Camel processes that name for retrieval, deletion, or renaming. Retrieval is part of normal consumer behavior, while deletion and renaming depend on endpoint disposition or read-lock configuration.
Exploit preconditions
- Attack surface: The remote-file consumer's processing of names returned by a remote directory listing
- Required access: The attacker generally needs control of, influence over, or the ability to tamper with the remote server's listing response; direct Camel authentication is not necessarily required
- Trigger point: Path construction before remote retrieval and subsequent file disposition operations
- Why exploitation is possible: The listing name is concatenated with the configured directory without lexical normalization or containment validation, allowing the resulting remote operand to resolve outside the polling directory
- Additional conditions: Deletion requires a delete-enabled disposition, and renaming requires move, preMove, moveFailed, or rename-based read-lock behavior; escape beyond the remote account's own boundary depends on server-side confinement
- Attack surface: The remote-file consumer's processing of names returned by a remote directory listing
- Required access: The attacker generally needs control of, influence over, or the ability to tamper with the remote server's listing response; direct Camel authentication is not necessarily required
- Trigger point: Path construction before remote retrieval and subsequent file disposition operations
- Why exploitation is possible: The listing name is concatenated with the configured directory without lexical normalization or containment validation, allowing the resulting remote operand to resolve outside the polling directory
- Additional conditions: Deletion requires a delete-enabled disposition, and renaming requires move, preMove, moveFailed, or rename-based read-lock behavior; escape beyond the remote account's own boundary depends on server-side confinement
Why this happens
The vulnerable pattern is constructing a filesystem or remote-file path by concatenating a trusted base directory with attacker-influenced path text, then using the result without canonicalization and an explicit containment check. Because directory-listing names were treated as ordinary file names, path components could alter the intended location. This maps to CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal'). A local-work-directory boundary did not compensate for the missing validation of the remote operand.
The vulnerable pattern is constructing a filesystem or remote-file path by concatenating a trusted base directory with attacker-influenced path text, then using the result without canonicalization and an explicit containment check. Because directory-listing names were treated as ordinary file names, path components could alter the intended location. This maps to CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal'). A local-work-directory boundary did not compensate for the missing validation of the remote operand.
Potential impact
- Camel may read files outside the configured remote polling directory.
- Camel may delete or rename remote files when the corresponding processing options are enabled.
- Sensitive data may be disclosed through downloaded or otherwise processed files.
- Files outside the intended directory may be altered, removed, or moved.
- An attacker could cause unauthorized operations using the endpoint's remote credentials.
- Route behavior or downstream processing may be disrupted through manipulated listing entries.
- Camel may read files outside the configured remote polling directory.
- Camel may delete or rename remote files when the corresponding processing options are enabled.
- Sensitive data may be disclosed through downloaded or otherwise processed files.
- Files outside the intended directory may be altered, removed, or moved.
- An attacker could cause unauthorized operations using the endpoint's remote credentials.
- Route behavior or downstream processing may be disrupted through manipulated listing entries.
General mitigation guidance
Mitigation generally focuses on treating remote listing names as untrusted input and enforcing the intended directory boundary for every remote operation.
Common defensive patterns include:
- Normalize and canonicalize candidate paths before retrieval, deletion, or renaming.
- Require the resolved path to remain beneath the configured polling directory, using a boundary-aware comparison rather than a simple string prefix.
- Prefer APIs that accept validated single-segment file names when directory traversal is not a valid requirement.
- Apply the same containment policy consistently across retrieval, deletion, move, preMove, moveFailed, and read-lock workflows.
- Reduce trust in remote listings through authenticated, integrity-protected transport and controlled server tenancy.
- Limit the remote account's permissions and confine it to the narrowest directory scope needed by the route.
- Keep local download directories separately constrained and use least-privilege filesystem permissions.
Mitigation generally focuses on treating remote listing names as untrusted input and enforcing the intended directory boundary for every remote operation.
Common defensive patterns include:
- Normalize and canonicalize candidate paths before retrieval, deletion, or renaming.
- Require the resolved path to remain beneath the configured polling directory, using a boundary-aware comparison rather than a simple string prefix.
- Prefer APIs that accept validated single-segment file names when directory traversal is not a valid requirement.
- Apply the same containment policy consistently across retrieval, deletion, move, preMove, moveFailed, and read-lock workflows.
- Reduce trust in remote listings through authenticated, integrity-protected transport and controlled server tenancy.
- Limit the remote account's permissions and confine it to the narrowest directory scope needed by the route.
- Keep local download directories separately constrained and use least-privilege filesystem permissions.
How teams detect issues like this
Organizations can look for this weakness through:
- Static analysis rules identifying concatenation of configured directories with listing-controlled names.
- Code review checks for missing normalization, canonicalization, or base-directory containment validation.
- Tests that supply parent-directory segments, absolute paths, alternate separators, and redundant path components in simulated listings.
- Policy checks requiring the same path-boundary validation before every remote file operation.
- Runtime monitoring for remote operations targeting paths outside the configured polling root.
- Automated security review tools that flag path construction from remote, archive, or protocol-derived input.
Organizations can look for this weakness through:
- Static analysis rules identifying concatenation of configured directories with listing-controlled names.
- Code review checks for missing normalization, canonicalization, or base-directory containment validation.
- Tests that supply parent-directory segments, absolute paths, alternate separators, and redundant path components in simulated listings.
- Policy checks requiring the same path-boundary validation before every remote file operation.
- Runtime monitoring for remote operations targeting paths outside the configured polling root.
- Automated security review tools that flag path construction from remote, archive, or protocol-derived input.
Sources
| Source | Link |
|---|---|
| camel. | camel.apache.org/ |
| github. | github.com/ |
| github. | github.com/ |
| github. | github.com/ |
| github. | github.com/ |
| issues. | issues.apache.org/ |
| github. | github.com/ |
