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10.27.2020

CVE-2020-11984 Apache HTTP Server Exploit 2.4.32 to 2.4.44 mod_proxy_uwsgi

Virsec Security Research Lab Vulnerability Analysis

The Virsec Security Research Lab provides detailed analysis on recent and notable security vulnerabilities.

Vulnerability Summary

Apache HTTP server 2.4.32 to 2.4.44 mod_proxy_uwsgi is vulnerable to info disclosure and possible RCE. A malicious request can easily overflow packet size by sending a small number of headers with a length that is close to the LimitRequestFieldSize default value of 8190. This can be used to trick UWSGI into parsing parts of the serialized subprocess environment as part of the POST body. An attacker might be able to leak sensitive environment variables as part of the POST body and/or strip security sensitive headers from the request. If UWSGI is explicitly configured in persistent mode (puwsgi), this can also be used to smuggle a second UWSGI request leading to remote code execution.

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CVSS Score

The CVSS Base score of this vulnerability is 9.8 (Critical).

Affected Version

Apache HTTP Server versions 2.4.32 to 2.4.43.

Vulnerability Attribution

As per Apache, this exploit has been discovered by Felix Wilhelm of Google Project Zero.

Risk Impact

The Apache HTTP Server is a powerful and flexible HTTP/1.1 compliant web server. Originally designed as a replacement for the NCSA HTTP Server, it has grown to be the most popular web server on the Internet. Apache HTTP Server is a tool in the Web Servers category of a tech stack.

Acording to Datanyze, Apache HTTP server has 49% of the market share in webserver market. An Attacker can exploit this Apache Vulnerability and cause a memory corruption, that can lead to RCE and damage the confidentiality, integrity, and availability of any of these vulnerable servers run by these companies. Publicly available exploits are available for this vulnerability.

Virsec Security Platform (VSP) Support

VSP-Host monitors processes that are spawned which are not part of a set of whitelisted process. Any attempt to execute new command or unknown binary would be denied by VSP-Host’s Process Monitoring capability.

Reference Links

Download the full vulnerability report to learn more about this and other important vulnerabilities.

About the Author
Satya Gupta is Virsec’s visionary founder, with over 25 years of expertise in embedded systems, network security and systems architecture. Satya has helped build and guide the company through key growth phases from initial funding (2015), developing core technology with key partners including Raytheon and Lockheed (2016-2018), to launching an enterprise class, GA product (2019). Prior to this, Satya built a highly profitable software design and consulting business targeting data networking, application security and industrial automation projects. He was also Director of Firmware Engineering at Narad Networks and Managing Director and Chief Engineer at Eastern Telecom and Tech Ltd. Satya has more than 40 patents in complex firmware architecture with products deployed to hundreds of thousands of users. He holds a BS degree in Engineering from the Indian Institute of Technology in Kanpur and additional degrees from the University of Massachusetts at Lowell.