Checking socks5 proxy before launching a scan

[osamahamad]

Is your feature request related to a problem? Please describe.
When using socks5 proxy and try to test a website / list of websites.

Example;

nuclei -t /x/nuclei-templates/vulnerabilities/jira/ -u https://tpx.sys.comcast.net -proxy-socks-url socks5://xaxa:xaxa@2.56.103.2:12888

nuclei response will be [INF] No results found in case -proxy-socks-url contains false credentials / wrong IP ..etc

when performing nuclei -t /x/nuclei-templates/vulnerabilities/jira/ -u https://tpx.sys.comcast.net
will result

[2021-09-08 14:46:13] [jira-unauthenticated-adminprojects] [http] [info] https://tpx.sys.comcast.net/rest/menu/latest/admin
[2021-09-08 14:46:13] [jira-unauthenticated-dashboards] [http] [info] https://tpx.sys.comcast.net/rest/api/2/dashboard?maxResults=100
[2021-09-08 14:46:13] [jira-unauthenticated-projectcategories] [http] [info] https://tpx.sys.comcast.net/rest/api/2/projectCategory?maxResults=1000
[2021-09-08 14:46:13] [jira-unauthenticated-resolutions] [http] [info] https://tpx.sys.comcast.net/rest/api/2/resolution
[2021-09-08 14:46:13] [jira-unauthenticated-installed-gadgets] [http] [info] https://tpx.sys.comcast.net/rest/config/1.0/directory

also, trying -proxy-socks-url with true credentials attempt will result in

[2021-09-08 14:46:13] [jira-unauthenticated-adminprojects] [http] [info] https://tpx.sys.comcast.net/rest/menu/latest/admin
[2021-09-08 14:46:13] [jira-unauthenticated-dashboards] [http] [info] https://tpx.sys.comcast.net/rest/api/2/dashboard?maxResults=100
[2021-09-08 14:46:13] [jira-unauthenticated-projectcategories] [http] [info] https://tpx.sys.comcast.net/rest/api/2/projectCategory?maxResults=1000
[2021-09-08 14:46:13] [jira-unauthenticated-resolutions] [http] [info] https://tpx.sys.comcast.net/rest/api/2/resolution
[2021-09-08 14:46:13] [jira-unauthenticated-installed-gadgets] [http] [info] https://tpx.sys.comcast.net/rest/config/1.0/directory

That being said, nuclei does not check if the -proxy-socks-url argument has a valid socks5 proxy before launching the scan. I wish it check argument value and in case the provided socks5 proxy is invalid due to wrong credentials supply or expired then nuclei will notify the user in stdout with something like ( proxy is invalid ) or Can't complete SOCKS5 connection to xxx port xxx and Ignore -proxy-socks-url argument and lunch the scan without proxy attempt ( the user might be able to control being able to perform the scan without proxy in case the proxy is invalid by additional flag )

Something like curl ; in the screenshot is an example when you supply true + false credentials.

This is helpful since most of the time since proxies can be used to avoid having your IP blocked by WAF or sometimes to bypass specific WAFs configurations. Also, most of the time proxies might get expired so the user supposed to know that and optionally being able to perform a scan with ignoring proxy flag ( specially if nuclei command used in a script ) is a plus.

[forgedhallpass]

Hello @osamahamad,

Your request makes sense, and we can definitely add such validations, although I am not sure ignoring the proxy in case of errors is a good idea. Quite the opposite actually, because it might give a false sense of security to those who would want to mask their IP addresses. As an enhancement, we could accept a file with a list of proxies and nuclei could go through them until it finds a working one, but if none of them are valid, I think the application should exit with an error code. If you want to default to no-proxy, then you could adjust your automation script to do so, based on the exit code.

[forgedhallpass]

Proposed solution:

• consolidate the -proxy-url and -proxy-socks-url flags
• remove the -proxy-sock-url flag
• decide on the proxy type based on the value prefix:
• http (e.g. http[s]://[user:password]@proxyurl[:port])
• socks (e.g. socks4://proxyurl[:port], socks5://[user:password]@proxyurl[:port])
• if none of the above, try using the input as file path (absolute or relative to the working directory) and try to use the first line as proxy. If that fails, move to the next, until a valid proxy is found or the EOF is reached.
• If a valid proxy is found, also set the HTTP_PROXY environmental variable to the same value. If os.Setenv() returns with an error then log it (-vv) and ignore the error