For more information regarding the security incident at F5, the actions we are taking to address it, and our ongoing efforts to protect our customers, click here.

Forum Discussion

EdgardoDeGracia's avatar
EdgardoDeGracia
Icon for Nimbostratus rankNimbostratus
Apr 10, 2019

F5 Web Application CVE Signatures For AWS WAF - FALSE POSITIVE

I am using AWS and implemented the “F5 Web Application CVE Signatures For AWS WAF” manage rule from AWS marketplace.

 

I am copying the sample request that is false positive from the AWS WAF console.

 

201.218.201.171 /course/modedit.php F5 Web Application CVE Signatures For AWS WAF Block 14:49:50 Client information: Source IP: 201.218.201.171 Country: PA Rule within rule group: 659aaaee-c124-460c-a775-22927af70a2f Request line: Method: POST URI: /course/modedit.php Request headers: Host: cursos.campusvirtualsp.org Content-Length: 2678 user-agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:66.0) Gecko/20100101 Firefox/66.0 accept: text/html,application/xhtml+xml,application/xml;q=0.9,/;q=0.8 accept-language: es,en-US;q=0.7,en;q=0.3 accept-encoding: gzip, deflate, br referer: https://cursos.campusvirtualsp.org/course/modedit.php?update=34464&return=1 content-type: application/x-www-form-urlencoded upgrade-insecure-requests: 1 cookie: TinyMCE_toggle=id_config_text%3D0; _ga=GA1.2.1480395476.1554154100; _gid=GA1.2.2045071368.1554154100; SSESS03d1962463878d637285620850f8c2c7=7F0Y5UmL3_e2dNRJylnLULV1W1s0c7HQUBYJjTFZuG4; MoodleSession=3pghhd5stbsjo3sqh38grunal1; _gat=1

 

201.218.201.171 /course/modedit.php F5 Web Application CVE Signatures For AWS WAF Block 14:50:46 Client information: Source IP: 201.218.201.171 Country: PA Rule within rule group: 659aaaee-c124-460c-a775-22927af70a2f Request line: Method: POST URI: /course/modedit.php Request headers: Host: cursos.campusvirtualsp.org Content-Length: 2689 user-agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:66.0) Gecko/20100101 Firefox/66.0 accept: text/html,application/xhtml+xml,application/xml;q=0.9,/;q=0.8 accept-language: es,en-US;q=0.7,en;q=0.3 accept-encoding: gzip, deflate, br referer: https://cursos.campusvirtualsp.org/course/modedit.php?update=34480&return=1 content-type: application/x-www-form-urlencoded upgrade-insecure-requests: 1 cookie: TinyMCE_toggle=id_config_text%3D0; _ga=GA1.2.1480395476.1554154100; _gid=GA1.2.2045071368.1554154100; SSESS03d1962463878d637285620850f8c2c7=7F0Y5UmL3_e2dNRJylnLULV1W1s0c7HQUBYJjTFZuG4; MoodleSession=3pghhd5stbsjo3sqh38grunal1; _gat=1

 

The rule block me when I tried to update a course configuration in Moodle. Bellow, I am sharing a web form where the rule is blocking.

 

 

4 Replies

  • There is no solution to this false positive? Is not possible to update a simple quiz activity in Moodle thanks to this AWS rule?

     

    • boneyard's avatar
      boneyard
      Icon for MVP rankMVP

      i would contact F5 support about it if you can.

       

      im not very familiar with ASM in AWS, you can't disable that one signature?

       

    • EdgardoDeGraci1's avatar
      EdgardoDeGraci1
      Icon for Nimbostratus rankNimbostratus

      I contacted F5 support and told me to post this issue as a question on DevCentral. The only solution I found is to change my subscription in AWS to another provider of WAF RuleGroups.

       

  • Please follow the procedure detailed in K21015971: Overview of F5 RuleGroups for AWS WAF

     

    Reporting false positives on DevCentral

     

    With full request logging you can now report on a rule that generates too many false positives. To report false positives, complete the following:

     

    • Log three to five requests that the rule has flagged as malicious requests.
    • Make sure that the requests do not contain any sensitive information; if they do, please mask the sensitive data with ****.
    • Attach the requests to a message (Ask a Question) on the DevCentral Answers forum.