Memory Leak in Privoxy Client-Tags CGI Handler (CVE-2021-20214)
Summary
CVE-2021-20214: A flaw was found in Privoxy in versions before 3.0.29. Affects privoxy versions < 3.0.29-r0. Fixed in 3.0.29-r0. How to fix ↓
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Background
Privoxy is an open-source web proxy server that provides advanced filtering capabilities for enhancing privacy, security, and anonymity while browsing the internet. It acts as an intermediary between the user's device and the web server, filtering and modifying web page content according to predefined rules. Privoxy is commonly used to block ads, remove tracking cookies, and protect against malicious scripts. However, a vulnerability has been discovered in Privoxy versions before 3.0.29 that can lead to a system crash due to memory leaks in the client-tags CGI handler when client tags are configured and memory allocations fail.
Vulnerability Detail
The vulnerability (CVE-2021-20214) in Privoxy arises from memory leaks in the client-tags CGI handler. When client tags are configured and memory allocations fail, the system can crash. This vulnerability can be exploited by an attacker to cause a denial-of-service (DoS) condition, potentially disrupting the availability of the Privoxy server. The impact of this vulnerability is limited to the Privoxy server itself and does not directly expose sensitive user information or allow remote code execution.
How To Fix
Minimum fixed version
3.0.29-r0
This is the first release that contains the fix.
sudo apk add --upgrade privoxyTip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
If upgrading Privoxy is not immediately feasible, a temporary workaround can be implemented by disabling or reconfiguring the client tags feature. By removing or modifying the client tags configuration, the memory allocation failures that trigger the vulnerability can be avoided. However, it is important to note that this workaround may impact the functionality or desired behavior of Privoxy, and upgrading to the latest version is still recommended for a comprehensive fix.
Conclusion
In conclusion, the vulnerability (CVE-2021-20214) in Privoxy versions before 3.0.29 can lead to a system crash due to memory leaks in the client-tags CGI handler. Upgrading Privoxy to the latest version is the recommended solution to address this vulnerability. If immediate upgrade is not possible, a temporary workaround involving the reconfiguration of client tags can be implemented. For further support and assistance in vulnerability remediation, please contact DevNack.com.
See every vulnerability recorded for privoxy →
FAQ
Privoxy is an open-source web proxy server that enhances privacy, security, and anonymity while browsing the internet. It filters and modifies web page content based on predefined rules, commonly used for blocking ads, removing tracking cookies, and protecting against malicious scripts.
The vulnerability (CVE-2021-20214) in Privoxy can lead to a system crash due to memory leaks in the client-tags CGI handler. While it does not directly expose sensitive user information or allow remote code execution, it can cause a denial-of-service (DoS) condition, potentially disrupting the availability of the Privoxy server.
To fix this vulnerability, it is recommended to upgrade Privoxy to version 3.0.29 or later. This upgrade addresses the memory leaks in the client-tags CGI handler. Instructions for upgrading Privoxy can be found in the official documentation or the package manager's repository.
If upgrading Privoxy is not immediately feasible, a temporary workaround involves disabling or reconfiguring the client tags feature. By removing or modifying the client tags configuration, the memory allocation failures that trigger the vulnerability can be avoided. However, it is important to note that this workaround may impact the functionality or desired behavior of Privoxy.
No, this vulnerability does not directly expose sensitive user information. Its impact is limited to the Privoxy server itself, potentially causing a denial-of-service (DoS) condition.
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