Directory Traversal Affecting org.apache.camel:camel-docling package, versions [4.15.0,4.18.5)[4.19.0,4.22.2)

Affected versions of this package are vulnerable to Directory Traversal via the validatePathSafety method in the Docling producer. An attacker can make the external docling process use a directory accessible to the Camel process, outside the intended working directory, by supplying an absolute path in the CamelDoclingCustomArguments header, such as a value for --artifacts-path. This affects CLI mode, the default, when a route or consumer allows externally controlled values into that header.

Notes

• At message ingress, Camel’s default header filtering on consumers such as JMS and Kafka strips Camel-prefixed headers; reaching this flaw through an incoming header requires that filtering to be bypassed or externally influenced data to be copied into CamelDoclingCustomArguments by the route.

Workarounds

• Do not build CamelDoclingCustomArguments from externally sourced values; this prevents external parties from choosing paths passed to the docling process.
• Remove CamelDoclingCustomArguments from messages arriving from outside before they reach a Docling endpoint, and configure consumers that map incoming headers to drop the Camel header namespace; this prevents incoming headers from supplying attacker-controlled paths.

A Directory Traversal attack (also known as path traversal) aims to access files and directories that are stored outside the intended folder. By manipulating files with "dot-dot-slash (../)" sequences and its variations, or by using absolute file paths, it may be possible to access arbitrary files and directories stored on file system, including application source code, configuration, and other critical system files.

Directory Traversal vulnerabilities can be generally divided into two types:

• Information Disclosure: Allows the attacker to gain information about the folder structure or read the contents of sensitive files on the system.

st is a module for serving static files on web pages, and contains a vulnerability of this type. In our example, we will serve files from the public route.

If an attacker requests the following URL from our server, it will in turn leak the sensitive private key of the root user.

curl http://localhost:8080/public/%2e%2e/%2e%2e/%2e%2e/%2e%2e/%2e%2e/root/.ssh/id_rsa

Note %2e is the URL encoded version of . (dot).

• Writing arbitrary files: Allows the attacker to create or replace existing files. This type of vulnerability is also known as Zip-Slip.

One way to achieve this is by using a malicious zip archive that holds path traversal filenames. When each filename in the zip archive gets concatenated to the target extraction folder, without validation, the final path ends up outside of the target folder. If an executable or a configuration file is overwritten with a file containing malicious code, the problem can turn into an arbitrary code execution issue quite easily.

The following is an example of a zip archive with one benign file and one malicious file. Extracting the malicious file will result in traversing out of the target folder, ending up in /root/.ssh/ overwriting the authorized_keys file:

2018-04-15 22:04:29 .....           19           19  good.txt
2018-04-15 22:04:42 .....           20           20  ../../../../../../root/.ssh/authorized_keys

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