CVE-2021-21419 : Exploit Details and Defense Strategies
Learn about CVE-2021-21419 impacting Eventlet, allowing memory exhaustion by sending compressed data. Mitigate the vulnerability with patches and updates.
Eventlet, a concurrent networking library for Python, is affected by a vulnerability that allows a websocket peer to exhaust memory by sending large frames. This can be exploited by a malicious peer sending highly compressed data. The issue, with a CVSS base score of 5.3, can lead to machine exhaustion. Learn how to mitigate and prevent this vulnerability.
Understanding CVE-2021-21419
Eventlet, a popular Python library, is vulnerable to memory exhaustion due to improper handling of highly compressed data and memory allocation.
What is CVE-2021-21419?
CVE-2021-21419 is a vulnerability in Eventlet where a websocket peer can exhaust memory by sending large frames, leading to an overall machine exhaustion.
The Impact of CVE-2021-21419
The vulnerability in Eventlet can be exploited by a malicious peer to exhaust memory using highly compressed data, impacting the availability of the system.
Technical Details of CVE-2021-21419
The following technical details are associated with CVE-2021-21419:
Vulnerability Description
A websocket peer in Eventlet can exhaust memory by sending very large frames, causing machine exhaustion.
Affected Systems and Versions
Eventlet versions from >= 0.10 to < 0.31.0 are affected by this vulnerability.
Exploitation Mechanism
Malicious peers can exploit this vulnerability by sending highly compressed data frames to exhaust memory.
Mitigation and Prevention
To address CVE-2021-21419 and prevent exploitation, consider the following steps:
Immediate Steps to Take
Implement the patch available in version 0.31.0 of Eventlet to restrict websocket frames to reasonable limits. Additionally, consider restricting memory usage via OS limits.
Long-Term Security Practices
Regularly update Eventlet to the latest version and follow secure coding practices to mitigate similar vulnerabilities in the future.
Patching and Updates
Stay informed about security advisories for Eventlet and promptly apply patches and updates to protect against known vulnerabilities.