Apache2 Denial of Service Vulnerability - CVE-2018-8011
Summary
ALPINE-CVE-2018-8011: By specially crafting HTTP requests, the mod_md challenge handler would dereference a NULL pointer and cause the child process to segfault. Affects apache2 versions < 2.4.34-r0. Fixed in 2.4.34-r0. How to fix ↓
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Background
Apache HTTP Server, commonly referred to as Apache2, is a widely used open-source web server software that enables the hosting of websites and applications. It is known for its flexibility, security features, and extensive module support. However, it is susceptible to various vulnerabilities, including CVE-2018-8011, which affects its mod_md challenge handler, leading to potential denial of service (DoS) attacks.
Vulnerability Detail
The vulnerability identified as CVE-2018-8011 arises from a flaw in the mod_md challenge handler of Apache2. By sending specially crafted HTTP requests, an attacker can trigger a NULL pointer dereference, causing the server's child process to segfault. This results in a denial of service, making the server temporarily unavailable to legitimate users. The vulnerability affects Apache HTTP Server version 2.4.33 and earlier, with a CVSS score of 7.5, indicating a high severity level.
How To Fix
Minimum fixed version
2.4.34-r0
This is the first release that contains the fix.
sudo apk add --upgrade apache2Tip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a temporary workaround, you can disable the mod_md module if it is not essential for your application. This can be done by commenting out the relevant LoadModule directive in the Apache configuration file, typically located at /etc/httpd/conf/httpd.conf.
Conclusion
In summary, CVE-2018-8011 is a significant vulnerability affecting Apache HTTP Server that can lead to denial of service attacks. It is crucial for users to update their Apache2 installations to the latest patched version to mitigate this risk. Utilizing tools like Vulert can help monitor and manage vulnerabilities effectively.
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FAQ
CVE-2018-8011 is a vulnerability in Apache HTTP Server that allows attackers to cause a denial of service by sending specially crafted HTTP requests.
You can use Vulert, which monitors open-source vulnerabilities in your software using a manifest file like package-lock.json. Visit Vulert Scanner to check your application without signup.
Apache HTTP Server versions 2.4.33 and earlier are affected by CVE-2018-8011. It is recommended to upgrade to version 2.4.34 or later.
The primary impact of CVE-2018-8011 is a denial of service, which can make the server temporarily unavailable to users, potentially affecting business operations.
Yes, the permanent fix is to update the Apache2 package to version 2.4.34 or later, which addresses the vulnerability.
References
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