diff --git a/modules/exploits/linux/http/nagios_xi_chained_rce.rb b/modules/exploits/linux/http/nagios_xi_chained_rce.rb
index 56c3414736..211d4d4f9d 100644
--- a/modules/exploits/linux/http/nagios_xi_chained_rce.rb
+++ b/modules/exploits/linux/http/nagios_xi_chained_rce.rb
@@ -63,13 +63,16 @@ class MetasploitModule < Msf::Exploit::Remote
     return unless res && (html = res.get_html_document)
 
     if (version = html.at('//input[@name = "version"]/@value'))
+      version = version.value
       vprint_status("Nagios XI version: #{version}")
       if Rex::Version.new(version) <= target[:version]
         return CheckCode::Appears("Version #{version} appears to be vulnerable")
       end
     end
 
-    CheckCode::Safe("Version #{version} is not vulnerable")
+    return CheckCode::Safe("Version #{version} is not vulnerable") if version
+
+    CheckCode::Unknown('Could not determine Nagios XI version')
   end
 
   def exploit
diff --git a/modules/exploits/linux/http/netgear_dnslookup_cmd_exec.rb b/modules/exploits/linux/http/netgear_dnslookup_cmd_exec.rb
index df43d160fe..6c8b65a6c9 100644
--- a/modules/exploits/linux/http/netgear_dnslookup_cmd_exec.rb
+++ b/modules/exploits/linux/http/netgear_dnslookup_cmd_exec.rb
@@ -73,6 +73,8 @@ class MetasploitModule < Msf::Exploit::Remote
       marker_one = "Basic realm=\"NETGEAR "
       marker_two = "\""
       model = data[/#{marker_one}(.*?)#{marker_two}/m, 1]
+      return CheckCode::Unknown('Could not determine NETGEAR model') if model.nil?
+
       vprint_status("Router is a NETGEAR router (#{model})")
       model_numbers = ['DGN2200v1', 'DGN2200v2', 'DGN2200v3', 'DGN2200v4']
       if model_numbers.include?(model)
@@ -83,7 +85,7 @@ class MetasploitModule < Msf::Exploit::Remote
       end
     else
       print_error('Router is not a NETGEAR router')
-      return CheckCode::Safe('Router is not a NETGEAR router')
+      return CheckCode::Safe('NETGEAR router not detected')
     end
   end
 
diff --git a/modules/exploits/linux/http/netgear_r7000_cgibin_exec.rb b/modules/exploits/linux/http/netgear_r7000_cgibin_exec.rb
index a0e2983102..324ad16970 100644
--- a/modules/exploits/linux/http/netgear_r7000_cgibin_exec.rb
+++ b/modules/exploits/linux/http/netgear_r7000_cgibin_exec.rb
@@ -71,6 +71,8 @@ class MetasploitModule < Msf::Exploit::Remote
       marker_one = "Basic realm=\"NETGEAR "
       marker_two = "\""
       model = scrape(data, marker_one, marker_two)
+      return CheckCode::Unknown('Could not determine NETGEAR model') if model.nil?
+
       vprint_status("Router is a NETGEAR router (#{model})")
       if model == 'R7000' || model == 'R6400'
         print_good("Router may be vulnerable (NETGEAR #{model})")
diff --git a/modules/exploits/linux/http/oracle_ebs_rce_cve_2022_21587.rb b/modules/exploits/linux/http/oracle_ebs_rce_cve_2022_21587.rb
index 1d82b838f6..ac4e602103 100644
--- a/modules/exploits/linux/http/oracle_ebs_rce_cve_2022_21587.rb
+++ b/modules/exploits/linux/http/oracle_ebs_rce_cve_2022_21587.rb
@@ -87,7 +87,7 @@ class MetasploitModule < Msf::Exploit::Remote
       return CheckCode::Safe("Oracle EBS version #{version} detected.")
     end
 
-    CheckCode::Detected('Oracle EBS detected, but the version could not be determined from the response.')
+    CheckCode::Unknown('Oracle EBS detected, but the version could not be determined')
   end
 
   def exploit
diff --git a/modules/exploits/linux/http/pretalx_rce_cve_2023_28458.rb b/modules/exploits/linux/http/pretalx_rce_cve_2023_28458.rb
index f82ecbf1f9..3fdc2c6092 100644
--- a/modules/exploits/linux/http/pretalx_rce_cve_2023_28458.rb
+++ b/modules/exploits/linux/http/pretalx_rce_cve_2023_28458.rb
@@ -57,7 +57,7 @@ class MetasploitModule < Msf::Exploit::Remote
   end
 
   def check
-    return CheckCode::Unknown('Login failed, please check credentials') unless login(datastore['EMAIL'], datastore['PASSWORD'])
+    return Exploit::CheckCode::Unknown('Login failed, please check credentials') unless login(datastore['EMAIL'], datastore['PASSWORD'])
 
     @logged_in = true
 
@@ -77,7 +77,7 @@ class MetasploitModule < Msf::Exploit::Remote
   rescue SessionCookieError
     return Exploit::CheckCode::Detected('Pretalx detected, failed to get session cookie - check your credentials')
   rescue DebugError
-    return Exploit::Checkcode::Detected('Failed to check if debug mode is enabled')
+    return Exploit::CheckCode::Detected('Failed to check if debug mode is enabled')
   end
 
   def exploit
diff --git a/modules/exploits/linux/http/rconfig_ajaxarchivefiles_rce.rb b/modules/exploits/linux/http/rconfig_ajaxarchivefiles_rce.rb
index 541b4eae0c..8dd152497d 100644
--- a/modules/exploits/linux/http/rconfig_ajaxarchivefiles_rce.rb
+++ b/modules/exploits/linux/http/rconfig_ajaxarchivefiles_rce.rb
@@ -76,16 +76,19 @@ class MetasploitModule < Msf::Exploit::Remote
       'uri' => '/login.php'
     )
     if !res || !res.get_html_document
-      return Exploit::CheckCode::Unknown('Could not check rConfig version')
-    end
-    if res.get_html_document.at('div[@id="footer-copyright"]').text.include? 'rConfig Version 3.9'
-      print_good('rConfig version 3.9 detected')
-      return Exploit::CheckCode::Appears('The target appears to be vulnerable')
-    elsif res.get_html_document.at('div[@id="footer-copyright"]').text.include? 'rConfig'
-      print_status('rConfig detected, but not version 3.9')
-      return Exploit::CheckCode::Detected('The target service was detected')
+      return Exploit::CheckCode::Unknown('Could not retrieve the rConfig login page')
     end
 
+    footer = res.get_html_document.at('div[@id="footer-copyright"]')
+    return Exploit::CheckCode::Unknown('Could not find version information on the login page') unless footer
+
+    if footer.text.include? 'rConfig Version 3.9'
+      print_good('rConfig version 3.9 detected')
+      return Exploit::CheckCode::Appears('rConfig version 3.9 was detected')
+    elsif footer.text.include? 'rConfig'
+      print_status('rConfig detected, but not version 3.9')
+      return Exploit::CheckCode::Detected('rConfig was detected but not version 3.9')
+    end
     Exploit::CheckCode::Safe('rConfig was not detected')
   end
 
diff --git a/modules/exploits/linux/http/samsung_srv_1670d_upload_exec.rb b/modules/exploits/linux/http/samsung_srv_1670d_upload_exec.rb
index ea63dce1e8..b1fa336302 100644
--- a/modules/exploits/linux/http/samsung_srv_1670d_upload_exec.rb
+++ b/modules/exploits/linux/http/samsung_srv_1670d_upload_exec.rb
@@ -87,7 +87,7 @@ class MetasploitModule < Msf::Exploit::Remote
       return CheckCode::Unknown('Could not determine the target version')
     end
 
-    CheckCode::Safe('The target is not vulnerable')
+    CheckCode::Safe('Samsung NVR not detected')
   end
 
   def exploit
diff --git a/modules/exploits/linux/http/vmware_vrops_mgr_ssrf_rce.rb b/modules/exploits/linux/http/vmware_vrops_mgr_ssrf_rce.rb
index 18740a0462..93fae1bff5 100644
--- a/modules/exploits/linux/http/vmware_vrops_mgr_ssrf_rce.rb
+++ b/modules/exploits/linux/http/vmware_vrops_mgr_ssrf_rce.rb
@@ -92,7 +92,7 @@ class MetasploitModule < Msf::Exploit::Remote
   end
 
   def check
-    leak_admin_creds ? CheckCode::Vulnerable('The target is vulnerable') : CheckCode::Safe('The target is not vulnerable')
+    leak_admin_creds ? CheckCode::Vulnerable('Successfully leaked admin credentials via SSRF') : CheckCode::Safe('Could not leak admin credentials via SSRF')
   end
 
   def exploit
diff --git a/modules/exploits/linux/http/webmin_packageup_rce.rb b/modules/exploits/linux/http/webmin_packageup_rce.rb
index 75409b7c4a..9e2b7955a1 100644
--- a/modules/exploits/linux/http/webmin_packageup_rce.rb
+++ b/modules/exploits/linux/http/webmin_packageup_rce.rb
@@ -118,7 +118,7 @@ class MetasploitModule < Msf::Exploit::Remote
     end
     print_error("#{datastore['USERNAME']} doesn't have the right to >>Package Update<<")
     print_status("Please try with another user account!")
-    CheckCode::Safe('The target is not vulnerable')
+    CheckCode::Detected("Version #{version} may be vulnerable, but user '#{datastore['USERNAME']}' lacks Package Updates permissions")
   end
 
   def exploit
diff --git a/modules/exploits/linux/http/zenoss_showdaemonxmlconfig_exec.rb b/modules/exploits/linux/http/zenoss_showdaemonxmlconfig_exec.rb
index 6fa3bb94b9..c5928bef7c 100644
--- a/modules/exploits/linux/http/zenoss_showdaemonxmlconfig_exec.rb
+++ b/modules/exploits/linux/http/zenoss_showdaemonxmlconfig_exec.rb
@@ -71,6 +71,7 @@ class MetasploitModule < Msf::Exploit::Remote
         'method' => "GET",
         'uri' => "/zport/acl_users/cookieAuthHelper/login_form"
       })
+      return Exploit::CheckCode::Unknown('No response received from the target') unless res
       return Exploit::CheckCode::Appears('The target appears to be vulnerable') if res.body =~ /<p>Copyright &copy; 2005-20[\d]{2} Zenoss, Inc\. \| Version\s+<span>3\./
       return Exploit::CheckCode::Detected('The target service was detected') if res.body =~ /<link rel="shortcut icon" type="image\/x\-icon" href="\/zport\/dmd\/favicon\.ico" \/>/
 
diff --git a/modules/exploits/linux/http/zyxel_lfi_unauth_ssh_rce.rb b/modules/exploits/linux/http/zyxel_lfi_unauth_ssh_rce.rb
index 48ffec4966..941161a898 100644
--- a/modules/exploits/linux/http/zyxel_lfi_unauth_ssh_rce.rb
+++ b/modules/exploits/linux/http/zyxel_lfi_unauth_ssh_rce.rb
@@ -415,7 +415,8 @@ class MetasploitModule < Msf::Exploit::Remote
     # @config = { 'hardware' => nil, 'software' => nil, 'serial' => nil, 'ssh_user' => nil, 'ssh_port' => nil, 'ssh_wan_access' => nil, 'ssh_service_enabled' => nil }
 
     res = get_configuration
-    return CheckCode::Unknown('Could not retrieve the target configuration') if res.nil? || res.code != 200
+    return CheckCode::Unknown('No response received from the target') if res.nil?
+    return CheckCode::Unknown('Could not retrieve the target configuration') if res.code != 200
 
     begin
       process_configuration(res)
diff --git a/modules/exploits/linux/ids/alienvault_centerd_soap_exec.rb b/modules/exploits/linux/ids/alienvault_centerd_soap_exec.rb
index 641d439f52..4325285aba 100644
--- a/modules/exploits/linux/ids/alienvault_centerd_soap_exec.rb
+++ b/modules/exploits/linux/ids/alienvault_centerd_soap_exec.rb
@@ -80,7 +80,7 @@ class MetasploitModule < Msf::Exploit::Remote
       version = ::Regexp.last_match(1)
     end
 
-    return CheckCode::Safe if version.blank?
+    return CheckCode::Unknown('Could not determine AlienVault version') if version.blank?
 
     if version >= '4.7.0'
       return CheckCode::Safe("AlienVault version #{version} is not vulnerable")
diff --git a/modules/exploits/linux/misc/hid_discoveryd_command_blink_on_unauth_rce.rb b/modules/exploits/linux/misc/hid_discoveryd_command_blink_on_unauth_rce.rb
index 315e3e4660..62a4947232 100644
--- a/modules/exploits/linux/misc/hid_discoveryd_command_blink_on_unauth_rce.rb
+++ b/modules/exploits/linux/misc/hid_discoveryd_command_blink_on_unauth_rce.rb
@@ -70,9 +70,14 @@ class MetasploitModule < Msf::Exploit::Remote
     end
 
     hid_res = parse_discovered_response res
+    unless hid_res
+      vprint_error 'Unexpected response from target'
+      return CheckCode::Unknown('Unexpected response from target')
+    end
+
     if hid_res[:mac].eql? ''
       vprint_error 'Malformed response'
-      return CheckCode::Safe
+      return CheckCode::Unknown('Received malformed response from target')
     end
 
     @mac = hid_res[:mac]
diff --git a/modules/exploits/linux/misc/qnap_transcode_server.rb b/modules/exploits/linux/misc/qnap_transcode_server.rb
index 8a2dbf6bd5..32b3adab32 100644
--- a/modules/exploits/linux/misc/qnap_transcode_server.rb
+++ b/modules/exploits/linux/misc/qnap_transcode_server.rb
@@ -70,7 +70,7 @@ class MetasploitModule < Msf::Exploit::Remote
 
     if res.blank?
       vprint_status 'No reply from server'
-      return CheckCode::Safe
+      return CheckCode::Unknown('No reply received from the transcode server')
     end
 
     vprint_status "Received response: #{res}"
diff --git a/modules/exploits/linux/misc/ueb9_bpserverd.rb b/modules/exploits/linux/misc/ueb9_bpserverd.rb
index a34c822968..6be885b31a 100644
--- a/modules/exploits/linux/misc/ueb9_bpserverd.rb
+++ b/modules/exploits/linux/misc/ueb9_bpserverd.rb
@@ -64,10 +64,12 @@ class MetasploitModule < Msf::Exploit::Remote
 
     # check if it's a valid port number (1-65534)
     if bpd_port && bpd_port >= 1 && bpd_port <= 65535
-      Exploit::CheckCode::Detected
+      Exploit::CheckCode::Detected('Target service detected on expected port')
     else
-      Exploit::CheckCode::Safe
+      Exploit::CheckCode::Safe('Target did not return a valid port number')
     end
+  ensure
+    disconnect(s1) if s1
   end
 
   def execute_command(cmd, opts = {})
diff --git a/modules/exploits/linux/misc/zabbix_server_exec.rb b/modules/exploits/linux/misc/zabbix_server_exec.rb
index 3807222e8e..f2359216c7 100644
--- a/modules/exploits/linux/misc/zabbix_server_exec.rb
+++ b/modules/exploits/linux/misc/zabbix_server_exec.rb
@@ -100,7 +100,7 @@ class MetasploitModule < Msf::Exploit::Remote
         return Exploit::CheckCode::Safe
       end
     else # No response
-      return Exploit::CheckCode::Safe
+      return Exploit::CheckCode::Unknown('No response received from the target')
     end
 
     # Retry with the good node_id
diff --git a/modules/exploits/linux/samba/lsa_transnames_heap.rb b/modules/exploits/linux/samba/lsa_transnames_heap.rb
index 7ff460ad64..e3fd887d3e 100644
--- a/modules/exploits/linux/samba/lsa_transnames_heap.rb
+++ b/modules/exploits/linux/samba/lsa_transnames_heap.rb
@@ -224,8 +224,8 @@ class MetasploitModule < Msf::Exploit::Remote
     end
 
     CheckCode::Safe
-  rescue StandardError
-    return CheckCode::Safe
+  rescue StandardError => e
+    return CheckCode::Unknown("Unable to determine: #{e.class} - #{e.message}")
   end
 
   def brute_exploit(target_addrs)
diff --git a/modules/exploits/linux/snmp/awind_snmp_exec.rb b/modules/exploits/linux/snmp/awind_snmp_exec.rb
index db275d3ab0..dfbac12f80 100644
--- a/modules/exploits/linux/snmp/awind_snmp_exec.rb
+++ b/modules/exploits/linux/snmp/awind_snmp_exec.rb
@@ -87,7 +87,9 @@ class MetasploitModule < Msf::Exploit::Remote
       model = sys_description.scan(/Crestron Electronics (AM-100|AM-101)/).flatten.first
       case model
       when 'AM-100', 'AM-101'
-        return CheckCode::Vulnerable
+        return CheckCode::Vulnerable("Detected vulnerable #{model} device")
+      when nil
+        return CheckCode::Unknown("SNMP sysDescr did not match a known vulnerable model: #{sys_description}")
       else
         # TODO: insert description check for other vulnerable models (that I don't have)
         # In the meantime, we return 'safe'.
diff --git a/modules/exploits/linux/ssh/vyos_restricted_shell_privesc.rb b/modules/exploits/linux/ssh/vyos_restricted_shell_privesc.rb
index 58b851dce3..f6c0af4b6e 100644
--- a/modules/exploits/linux/ssh/vyos_restricted_shell_privesc.rb
+++ b/modules/exploits/linux/ssh/vyos_restricted_shell_privesc.rb
@@ -95,15 +95,15 @@ class MetasploitModule < Msf::Exploit::Remote
         ssh = Net::SSH.start(rhost, username, opts)
       end
     rescue Rex::ConnectionError
-      return CheckCode::Safe
+      return CheckCode::Unknown('Connection failed')
     rescue Net::SSH::Disconnect, ::EOFError
-      return CheckCode::Safe
+      return CheckCode::Unknown('Disconnected during SSH negotiation')
     rescue Timeout::Error
-      return CheckCode::Safe
+      return CheckCode::Unknown('Connection timed out')
     rescue Net::SSH::AuthenticationFailed
-      return CheckCode::Safe
+      return CheckCode::Detected('SSH service detected but authentication failed')
     rescue Net::SSH::Exception
-      return CheckCode::Safe
+      return CheckCode::Unknown('SSH error occurred')
     end
 
     CheckCode::Detected('SSH service detected.')
diff --git a/modules/exploits/linux/upnp/miniupnpd_soap_bof.rb b/modules/exploits/linux/upnp/miniupnpd_soap_bof.rb
index 981e6aab09..8e6ffc0685 100644
--- a/modules/exploits/linux/upnp/miniupnpd_soap_bof.rb
+++ b/modules/exploits/linux/upnp/miniupnpd_soap_bof.rb
@@ -92,7 +92,7 @@ class MetasploitModule < Msf::Exploit::Remote
         'uri' => '/'
       })
     rescue ::Rex::ConnectionError
-      return Exploit::CheckCode::Safe
+      return Exploit::CheckCode::Unknown('Connection failed')
     end
 
     fingerprints = targets.collect { |t| t['Fingerprint'] }