Apache Struts allows entering a custom URL in a form field if built-in URLValidator is used
        
  High severity
        
          GitHub Reviewed
      
        Published
          Oct 16, 2018 
          to the GitHub Advisory Database
          •
          Updated Jan 4, 2024 
      
  
Package
Affected versions
>= 2.3.7, <= 2.3.33
      >= 2.5.0, <= 2.5.12
  Patched versions
2.3.34
      2.5.13
  Description
        Published to the GitHub Advisory Database
      Oct 16, 2018 
    
  
        Reviewed
      Jun 16, 2020 
    
  
        Last updated
      Jan 4, 2024 
    
  
In Apache Struts 2.3.7 through 2.3.33 and 2.5 through 2.5.12, if an application allows entering a URL in a form field and built-in URLValidator is used, it is possible to prepare a special URL which will be used to overload server process when performing validation of the URL. NOTE: this vulnerability exists because of an incomplete fix for S2-047 / CVE-2017-7672.
References