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 addOutputDirectoryArguments method in the camel-docling component. An attacker who can influence the CamelDoclingOutputFilePath header can supply an absolute path or one containing .. segments, causing the Docling CLI to write the message’s converted document into any directory the Camel process can write to. This occurs in CLI mode, the default, when a route forwards an externally influenced header to the producer; the output file remains after the producer removes its temporary directory.

Notes

• On the entry path, external input must reach the Camel CamelDoclingOutputFilePath header: Camel’s default header filtering on consumers such as JMS and Kafka removes Camel-namespace headers, so those consumers need to map incoming headers without that filtering, or a route must set the header from external data.

Workarounds

• Do not build the CamelDoclingOutputFilePath header from values originating outside your deployment; this prevents external input from choosing where Docling writes converted files.
• Remove CamelDoclingOutputFilePath from messages arriving from outside before they reach a Docling endpoint; this prevents those messages from controlling the output path.
• Configure consumers that map incoming message headers to drop the Camel header namespace; this prevents externally supplied Camel headers from reaching Docling routes.

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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