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CVE-2020-1938

  • 1.  CVE-2020-1938

    Posted 15 days ago

    CVE 2020-1938

    When using the Apache JServ Protocol (AJP), care must be taken when trusting incoming connections to Apache Tomcat. Tomcat treats AJP connections as having higher trust than, for example, a similar HTTP connection. If such connections are available to an attacker, they can be exploited in ways that may be surprising. In Apache Tomcat 9.0.0.M1 to 9.0.0.30, 8.5.0 to 8.5.50 and 7.0.0 to 7.0.99, Tomcat shipped with an AJP Connector enabled by default that listened on all configured IP addresses. It was expected (and recommended in the security guide) that this Connector would be disabled if not required. This vulnerability report identified a mechanism that allowed: - returning arbitrary files from anywhere in the web application - processing any file in the web application as a JSP Further, if the web application allowed file upload and stored those files within the web application (or the attacker was able to control the content of the web application by some other means) then this, along with the ability to process a file as a JSP, made remote code execution possible. It is important to note that mitigation is only required if an AJP port is accessible to untrusted users. Users wishing to take a defence-in-depth approach and block the vector that permits returning arbitrary files and execution as JSP may upgrade to Apache Tomcat 9.0.31, 8.5.51 or 7.0.100 or later. A number of changes were made to the default AJP Connector configuration in 9.0.31 to harden the default configuration. It is likely that users upgrading to 9.0.31, 8.5.51 or 7.0.100 or later will need to make small changes to their configurations.

    How does Imperva on prem waf handle this  CVE-2020-1938 as it is currently being mass scanned and exploited by threat actors.


    #On-PremisesWAF(formerlySecuresphere)

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    shamiel bhikha
    Blueturtle
    Midrand Johannesburg AL
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  • 2.  RE: CVE-2020-1938

    Community Manager
    Posted 15 days ago
    @shamiel bhikha, thank you for the question. I spoke to one of Imperva's developers and he said "Tge AJP port will not be accessible in reverse proxy mode. In other modes I suggest to add the AJP port as protected port and set the http protocol policy to block for that service. As AJP is a binary protocol all communication with that protocol should be blocked." 

    I hope this helps. If so, please Mark Best Answer. If you need more information, please let me know.

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    Christopher Detzel
    Community Manager
    Imperva
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