Learn about CVE-2022-42915, a double free vulnerability in curl before 7.86.0, potentially allowing arbitrary code execution. Find out impacted versions and mitigation steps.
CVE-2022-42915, discovered in curl before version 7.86.0, involves a double free vulnerability. The issue arises when curl is directed to use an HTTP proxy for a transfer with a non-HTTP(S) URL, potentially leading to a double free scenario. This vulnerability affects versions starting from 7.77.0.
Understanding CVE-2022-42915
This section delves into the specifics of CVE-2022-42915.
What is CVE-2022-42915?
The vulnerability in curl before 7.86.0 allows for a double free condition under specific circumstances. If the HTTP proxy rejects the CONNECT request and responds with a non-200 status code, it can trigger the double free in curl, leading to a potential security risk.
The Impact of CVE-2022-42915
The exploitation of this vulnerability could result in denial of service, sensitive data exposure, or possibly allow an attacker to execute arbitrary code on the affected system.
Technical Details of CVE-2022-42915
In this section, we discuss the technical aspects of CVE-2022-42915.
Vulnerability Description
The double free vulnerability in curl versions prior to 7.86.0 occurs when the HTTP proxy returns a non-200 status code following a CONNECT request, leading to memory corruption and potential risk of exploitation.
Affected Systems and Versions
All versions of curl from 7.77.0 up to 7.85.1 are affected by this vulnerability. Systems using curl in conjunction with an HTTP proxy for non-HTTP(S) URLs are at risk.
Exploitation Mechanism
To exploit this vulnerability, an attacker can craft a URL using one of the following schemes: dict, gopher, gophers, ldap, ldaps, rtmp, rtmps, or telnet, which triggers an error in the handling of the proxy response, leading to a double free condition in the curl codebase.
Mitigation and Prevention
This section outlines strategies to mitigate and prevent exploitation of CVE-2022-42915.
Immediate Steps to Take
Users are advised to update curl to version 7.86.0 or later to address this vulnerability. Additionally, implementing network-level protections and restricting the curl usage to trusted URLs can help reduce the risk of exploitation.
Long-Term Security Practices
Regularly updating software components, monitoring vendor security advisories, and maintaining a robust patch management strategy are essential long-term security practices to prevent similar vulnerabilities.
Patching and Updates
Users should prioritize patching their curl installations to the latest secure version available, following vendor recommendations and best practices for secure software maintenance.