CVE-2020-11709: 
Homebrew vulnerability analysis and mitigation

CVE-2020-11709 was a CRLF Injection vulnerability discovered in the cpp-httplib library affecting versions prior to 0.5.9. The vulnerability was found in the set_redirect and set_header functions, which were susceptible to HTTP response splitting attacks when handling untrusted user input (GitHub Issue).

The vulnerability existed in the library's Response class methods set_header and set_redirect, where user input was not properly sanitized for CRLF sequences. The code did not validate or escape the input parameters before using them in HTTP headers, allowing attackers to inject malicious CRLF sequences that could lead to HTTP response splitting attacks (GitHub POC).

The vulnerability could allow attackers to perform HTTP response splitting attacks by injecting CRLF sequences in header values. This could lead to response manipulation, cache poisoning, and potential cross-site scripting (XSS) attacks, compromising the security of applications using the affected library versions.

The vulnerability was fixed in cpp-httplib version 0.5.9. Users were advised to upgrade to this version or later to address the security issue. The fix involved proper validation and sanitization of input used in HTTP headers (GitHub Issue).