Synchronet v3.19b-Win32 (install) has been released (Jan-2022).

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howto:block-hackers [2023/12/17 21:52] – [Synchronet's Defense] from Permanent to Persistent digital manhowto:block-hackers [2024/05/14 22:11] (current) – [Synchronet's Defense] mention the failed login list sem files digital man
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   * Set the ''inactive_hangup'' setting in the ''[login]'' section of your ''[[dir:ctrl]]/[[config:modopts.ini]]'' file to terminate such //dumb// connections after just a short amount of inactivity (e.g. 30 seconds)   * Set the ''inactive_hangup'' setting in the ''[login]'' section of your ''[[dir:ctrl]]/[[config:modopts.ini]]'' file to terminate such //dumb// connections after just a short amount of inactivity (e.g. 30 seconds)
   * Make sure if you're using any "login matrix" or other 3rd party login module, especially those with animated prompts, that they include some kind of user-inactivity timeout and disconnection support((this is a surprisingly common flaw in custom animated pause prompt mods))   * Make sure if you're using any "login matrix" or other 3rd party login module, especially those with animated prompts, that they include some kind of user-inactivity timeout and disconnection support((this is a surprisingly common flaw in custom animated pause prompt mods))
 +  * Synchronet v3.20 added a new configuration option to help with this scenario: SCFG->Servers->Terminal Server->Max Login Inactivity (default: 10 minutes), also ''MaxLoginInactivity'' in the ''[BBS]'' section of ''[[config:sbbs.ini]]''
 ===== Synchronet's Defense ===== ===== Synchronet's Defense =====
 Synchronet normally disallows the use of common passwords by users (see the ''[[dir:text]]/password.can'' file) and system operator accounts are protected with a secondary "system password", so there should be little chance of a dictionary-based login attack actually succeeding. You can run ''[[dir:exec]]/badpasswords.js'' (e.g. using [[util:jsexec]]) to check your user database for common passwords if you wish. Synchronet normally disallows the use of common passwords by users (see the ''[[dir:text]]/password.can'' file) and system operator accounts are protected with a secondary "system password", so there should be little chance of a dictionary-based login attack actually succeeding. You can run ''[[dir:exec]]/badpasswords.js'' (e.g. using [[util:jsexec]]) to check your user database for common passwords if you wish.
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 Note: Note:
   * These IP addresses are only tracked during a single continuous invocation of the Synchronet process (rerunning the BBS clears the list and resets any temporary bans in effect)   * These IP addresses are only tracked during a single continuous invocation of the Synchronet process (rerunning the BBS clears the list and resets any temporary bans in effect)
 +  * Temporary IP address bans can be cleared (without resetting a server) by using [[config:semfiles#clear_failed_login_list_semaphore_files]]
   * Consecutive failed login attempts with the //same credentials// (name and password) are counted as a //single// failed login attempt   * Consecutive failed login attempts with the //same credentials// (name and password) are counted as a //single// failed login attempt
   * When a client successfully authenticates, its IP address is removed from the failed login list (if it exists there)   * When a client successfully authenticates, its IP address is removed from the failed login list (if it exists there)
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 Note: Setting the Temp Ban Threshold to 0 will disable temporary bans based on failed login attempt counters, but a failed login with a blocked name (from ''[[dir:text]]/name.can'') will still result in an immediate temporary ban, regardless of the Temp Ban Threshold value. Note: Setting the Temp Ban Threshold to 0 will disable temporary bans based on failed login attempt counters, but a failed login with a blocked name (from ''[[dir:text]]/name.can'') will still result in an immediate temporary ban, regardless of the Temp Ban Threshold value.
  
-=== Permanent Filtering ===+=== Persistent Filtering ===
  
-To permanently block future connections from an IP address that has performed multiple consecutive failed login attempts: +To persistently block future connections from an IP address that has performed multiple consecutive failed login attempts: 
-  * In the Synchronet Control Panel for Windows, set File->Properties->Security->Failed Login Attempts->Perm Filter Threshold value... (used to be called "IP Filter Threshold")+  * In the Synchronet Control Panel for Windows, set File->Properties->Security->Failed Login Attempts->Auto Filter Threshold value... (used to be called "IP Filter Threshold", then "Perm Filter Threshold")
   * or edit your ''[[dir:ctrl]]/[[config:sbbs.ini]]'' file and set the ''LoginAttemptFilterThreshold'' value...   * or edit your ''[[dir:ctrl]]/[[config:sbbs.ini]]'' file and set the ''LoginAttemptFilterThreshold'' value...
  
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 The default Filter Threshold value is 0 (disabled). The default Filter Threshold value is 0 (disabled).
  
-{{:monitor:sbbsctrl:sbbsctrl.security.png|}}+The //duration// of the persistent IP address filters that area automatically creates is also configurable (default: 0/infinite). 
 + 
 +{{:howto:sbbsctrl.3.20.security.png|}}
  
 Note: These ''LoginAttempt'' values may be set in your ''[[config:sbbs.ini]]'' to different values for each Synchronet server/service if you wish, but that's a configuration that most sysops won't need. Note: These ''LoginAttempt'' values may be set in your ''[[config:sbbs.ini]]'' to different values for each Synchronet server/service if you wish, but that's a configuration that most sysops won't need.