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custodian-enqueue
-----------------
We open named files from the user to parse tests. The configuration file(s)
are currently opened by root, via /etc/service/custodian-enqueue. This should
be changed to run as a lower-privileged user.
custodian-dequeue
-----------------
Two tests pass arguments from the configuration file to the shell:
ping
http/https
The hostname used to ping, and the URL for web-tests, are both passed directly to the shell with no encoding or sanitizing. The only issue is that the hostnames must match the following regular expression:
^([^\s]+)\s+
The following configuration file allows the specified command to be executed, as the user running the dequeue tool, via the shell:
$(/home/steve/hg/custodian/exploit.sh) must ping otherwise "Owned".
Given that anybody who can talk to the beanstalkd server can submit JSON-encoded-jobs we have no solution here which involves sanity-checking the parsed-hostnames. Instead we much either restrict submissions to signed ones, or we must remove the following from hostnames:
$( ... ) - Expansion.
` .. ` - Backticks.
; .. - Sub-commands.
That has not yet been done, but it is definitely on the map.
General
-------
We decode arbitrary JSON from the queue. We should sign it, or validate it to will prevent trojan malformed
JSON from being added.
At the moment we ensure that the job-body we retrieve looks JSON-like, and decodes to a non-empty hash.
Problem: We cannot sign the body without giving away our key details.
Solution: Read /etc/custodian/salt, and store the checksum of all keys + values with that salt?
TODO
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Anything else? DoS attacks?
Steve
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