http2 clear-text sessions are listed in the command output of "show session all filter ssl-decrypt yes"

http2 clear-text sessions are listed in the command output of "show session all filter ssl-decrypt yes"

696
Created On 07/29/22 19:06 PM - Last Modified 04/25/25 20:31 PM


Symptom


  • http2 clear-text sessions are listed  the 'show session all' filter with ssl-decrypt : "show session all filter ssl-decrypt yes"


Environment


Firewall with no ssl decryption configured however listing sessions in the output of the command "show session all filter ssl-decrypt yes" :

> show session all filter ssl-decrypt yes 
--------------------------------------------------------------------------------
ID          Application    State   Type Flag  Src[Sport]/Zone/Proto (translated IP[Port])
Vsys                                          Dst[Dport]/Zone (translated IP[Port])
--------------------------------------------------------------------------------

75054346     web-browsing   ACTIVE  FLOW *     10.174.253.60[43784]/untrust/6  (10.174.253.60[43784])
vsys1                                          10.254.252.33[7442]/trust  (10.254.252.33[7442])
76647546     web-browsing   ACTIVE  FLOW *     10.174.253.84[57978]/untrust/6  (10.174.253.84[57978])
vsys1                                          10.254.252.33[7442]/trust  (10.254.252.33[7442])
7786948
75998109     web-browsing   ACTIVE  FLOW *     10.175.192.19[5524]/untrust/6  (10.175.192.19[5524])
vsys1                                          10.254.252.189[11983]/trust  (10.254.252.189[11983])
 
> show running decryption-policy 

DP s1dp0:

DP s1dp1:

DP s1dp2:


Cause


  • This behaviour is seen because the command "show session all filter ssl-decrypt yes" shows the sessions which are proxy sessions whether decrypted or not.
  • The below output shows the http2 cleartext proxy sessions in the output of "show session all filter ssl-decrypt yes" even there are no ssl decrypted sessions  :
> show session all filter ssl-decrypt yes 
--------------------------------------------------------------------------------
ID          Application    State   Type Flag  Src[Sport]/Zone/Proto (translated IP[Port])
Vsys                                          Dst[Dport]/Zone (translated IP[Port])
--------------------------------------------------------------------------------

75054346     web-browsing   ACTIVE  FLOW *     10.174.253.60[43784]/untrust/6  (10.174.253.60[43784])
vsys1                                          10.254.252.33[7442]/trust  (10.254.252.33[7442])
76647546     web-browsing   ACTIVE  FLOW *     10.174.253.84[57978]/untrust/6  (10.174.253.84[57978])
vsys1                                          10.254.252.33[7442]/trust  (10.254.252.33[7442])
7786948
75998109     web-browsing   ACTIVE  FLOW *     10.175.192.19[5524]/untrust/6  (10.175.192.19[5524])
vsys1                                          10.254.252.189[11983]/trust  (10.254.252.189[11983])

 > show session all filter http2-connection yes 


--------------------------------------------------------------------------------
ID          Application    State   Type Flag  Src[Sport]/Zone/Proto (translated IP[Port])
Vsys                                          Dst[Dport]/Zone (translated IP[Port])
--------------------------------------------------------------------------------
73441871     web-browsing   ACTIVE  FLOW *     10.174.251.43[55308]/untrust/6  (10.174.251.43[55308])
vsys1                                          10.254.252.33[7442]/trust  (10.254.252.33[7442])
68201151     web-browsing   ACTIVE  FLOW *     10.174.250.136[50530]/untrust/6  (10.174.250.136[50530])
vsys1                                          10.254.252.33[7442]/trust  (10.254.252.33[7442])
76694385     web-browsing   ACTIVE  FLOW *     10.175.192.18[48784]/untrust/6  (10.175.192.18[48784])
vsys1                                           

> show counter global filter delta yes | match "http\|clear"
ctd_cleartext_proxy_start                  2        0 info      ctd       pktproc   Ctd session with cleartext proxy
proxy_cleartext_ingress                    2        0 info      proxy     pktproc   Number of cleartext proxy session started with proxy ingress
http2_process                              2        0 info      http2     pktproc   Number of http2 connection process


Resolution



Note that this observation may cause confusion since there is no ssl decryption and no active running ssl decryption policy but we still see the session in the output of the command "show session all filter ssl-decrypt yes".

As per the current design, it is expected behaviour to see the http2 clear-text proxy sessions in the output of the command "show session all filter ssl-decrypt yes".

There is an internal request open to review this behaviour and consider a possible change.


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