cpp-httplib Exposes Internal Error Messages to Any Client

Summary

A bug in cpp-httplib, a library used for creating web servers, allows any client to see internal error messages if the server crashes. This is a security issue because it could reveal sensitive information to attackers. To fix this, update to version 0.35.0 or later, or explicitly register an exception handler to prevent error messages from being sent to clients.

What to do

No fix is available yet. Check with your software vendor for updates.

Affected software

Vendor	Product	Affected versions	Fix available
yhirose	cpp-httplib	<= 0.35.0	–

Original title

cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to 0.35.0, when a request handler throws a C++ exception and the application has not registered a custom exce...

Original description

cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to 0.35.0, when a request handler throws a C++ exception and the application has not registered a custom exception handler via set_exception_handler(), the library catches the exception and writes its message directly into the HTTP response as a header named EXCEPTION_WHAT. This header is sent to whoever made the request, with no authentication check and no special configuration required to trigger it. The behavior is on by default. A developer who does not know to opt in to set_exception_handler() will ship a server that leaks internal exception messages to any client. This vulnerability is fixed in 0.35.0.

nvd CVSS3.1 5.3

Vulnerability type

CWE-200 Information Exposure

https://github.com/yhirose/cpp-httplib/commit/defd907c7469c5c8281247b73bbd07be24... Patch
https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-8mpw-r4gc-xm7q Exploit Mitigation Vendor Advisory