A
service that is run on
port 19. Many types of
operating systems run
varients of this service. Suprisingly, some new ones do also. It is generally not needed for anything vital, however it can be used to compromise
security and plays an important role in
DOS (
Denial of Service) attacks.
Recommendation:
Disable the service, unless it is needed.
In Unix:
To disable chargen when started from
inetd:
Edit the /etc/inetd.conf (or equivalent) file.
Locate the line that controls the chargen
daemon.
Type a # at the beginning of the line to comment out the daemon.
Restart inetd.
In Windows:
The chargen service is not
native to Windows, but may be present.
CAUTION: Use Registry Editor at your own risk. Any change
using Registry Editor may cause severe and irreparable
damage and may require you to reinstall your operating
system.
To disable only the chargen service:
1. Open the registry editor.
2. Go to: HKEY_LOCAL_MACHINE\SYSTEM\CURRENTCONTROLSET\SERVICES\SIMPTCP\PARAMETERS.
3. Double-click the EnableTcpChargen key to display the DWORD Editor.
4. Replace the value in the Data field with 0.
5. Click OK.
6. Repeat steps 3 through 5 for the EnableUdpChargen key.
7. To implement your changes, stop and restart the Simple
TCP/IP Service.
In Novell:
1.Install
NIAS4.0 or later.
2.Load INETCFG
—> Protocols —> TCP/IP, and set filter support to ENABLED.
3.Load FILTCFG —> TCP/IP —> Packet Forwarding filters, and set the status to ENABLED.
4.Verify that the action is Deny packets in filter list. Press ENTER on "(Filters: list of denied packets)".
5.Press INSERT go to packet type: Name: check all.
6.Press ENTER, find the port chargen TCP 19.
7.Press ENTER, ESCAPE, save filters: YES.