Sling Post servlet forbidden error .

hari_krishnac22

22-07-2020

HI Team,

version : 6.4

service pack : 6.4.4.0 

In fact author and publisher post servlets are failing . 

Sling post servlet failing with 403 error. From logs this is the information  com.adobe.granite.csrf.impl.CSRFFilter isValidRequest: empty csrf token - rejecting

  1. Request URL:
    https://diapctherurl :10500/services/content
  2. Request Method:
    POST
  3. Status Code:
    403 Forbidden

Followed the below steps : 

Step 1:

  • Navigated to /system/console/configMgr .
  • Search for 'Apache Sling Referrer Filter' .
  • Removed the  POST method from the filter.

Step 2:

  • Navigated to /system/console/configMgr .
  • Search for ‘Adobe Granite CSRF Filter’.
  • Removed the  POST method from the filters property.

After removed these 2 working fine. But client is  saying  since last week the post Servlet was worked fine, In fact no changes are  made in dispatcher, Thanks  in advacne. 

 

Thanks, 

Hari Chandana

Accepted Solutions (1)

Accepted Solutions (1)

Veena_Vikram

MVP

22-07-2020

Hi @hari_krishnac22 

 

   Since you have mentioned that everything was working fine till last week and nothing has changed I am not sure what is going wrong. But normally this error happens when the AEM doesn't sent the CSRF token along wiht the request. Jorg has answered a similar question here . Check if this helps

 

https://experienceleaguecommunities.adobe.com/t5/adobe-experience-manager/getting-csrf-token-as-inva...

 

Thanks

Veena

 

 

Answers (4)

Answers (4)

aemmarc

Employee

23-07-2020

Step 2 is not recommended.

 

The CSRF Filter essentially has 5 bits of logic it will filter on
 
1 - request.getAuthType() != null <-- this one is super common for organizations that have their own custom servlets that omit setting the authType on the request 
2 - this.isFilteredMethod(request) <-- this one is based on the OSGI Config for the CSRF framework, eg what methods POST / GET / DELETE etc  (this is what you deleted in Step2 -- not recommended)
3 - doFilterBasedOnUserAgent(request) <-- checks the user agent whitelist
4 - !isExcludedPath(request)) <-- checks if this path is to be excluded from CSRF OSGI config.
5 - !this.isValidRequest(request)) <-- checks for the CSRF-Token header in the request.
 
Hope that helps.

vanegi

Employee

22-07-2020

Hi @hari_krishnac22,

Can you check that a CSRF token is actually sent to the dispatcher? Can you enable debug logging on dispatcher and see if that header is transferred to the publish? The header name is "CSRF-Token". If it is not there, include the "CSRF-Token" under clientheaders in dispatcher config file.

 

Thanks!!