Denial of Service Vulnerability in Mojolicious Module (CVE-2021-47208)
Summary
CVE-2021-47208: The Mojolicious module before 9.11 for Perl has a bug in format detection that can potentially be exploited for denial of service. Affects libmojolicious-perl versions < a0c4576ffb11c235088550de9ba7ac4196e1953c. No fix is published. How to fix ↓
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Background
Mojolicious is a real-time web framework for Perl that simplifies the development of web applications. It is known for its non-blocking I/O and easy-to-use interface, allowing developers to create powerful web applications quickly. The vulnerability in question affects versions of the Mojolicious module prior to 9.11, where a bug in format detection can lead to potential denial of service attacks.
Vulnerability Detail
The vulnerability arises from a flaw in the format detection mechanism of the Mojolicious module. This bug can be exploited by an attacker to cause the application to become unresponsive, leading to a denial of service. The issue is particularly concerning for applications relying on Mojolicious for handling web requests, as it can severely impact availability and user experience. The vulnerability is present in all versions before 9.11, making it critical for users to update their installations.
How To Fix
No fixed version is published for this vulnerability.
To fix the vulnerability, users should upgrade the Mojolicious module to version 9.11 or later. This can typically be done using the package manager for your system. For Debian-based systems, you can run the following command:
sudo apt-get update
sudo apt-get install libmojolicious-perl
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Workaround
If upgrading is not immediately possible, consider implementing rate limiting or request validation to mitigate the risk of denial of service attacks. Additionally, monitor your application for unusual traffic patterns that may indicate an ongoing attack.
Conclusion
CVE-2021-47208 is a significant vulnerability in the Mojolicious module that can lead to denial of service. Users are strongly advised to upgrade to version 9.11 or later to protect their applications. For those unable to upgrade immediately, implementing workarounds can help mitigate potential risks.
See every vulnerability recorded for libmojolicious-perl →
FAQ
CVE-2021-47208 is a vulnerability in the Mojolicious module for Perl that can lead to denial of service due to a bug in format detection.
All versions of Mojolicious prior to 9.11 are affected by this vulnerability.
You can use Vulert to monitor and alert for open-source vulnerabilities in your software. Check your application against the vulnerability using the Vulert playground at Vulert Scanner.
The primary impact is denial of service, which can render your web application unresponsive and affect user access.
Yes, implementing rate limiting and monitoring for unusual traffic can help mitigate the risk until an upgrade is possible.
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