All versions of the package crow are vulnerable to HTTP Response Splitting when untrusted user input is used to build header values. Header values are not properly sanitized against CRLF Injection in the set_header and add_header functions. An attacker can add the \r\n (carriage return line feeds) characters to end the HTTP response headers and inject malicious content.

Crow before 1.3.4 Denial of Service via Deeply Nested JSON in crow::json::load()

Crow before 1.3.4 contains an uncontrolled recursion vulnerability in crow::json::load() that allows remote unauthenticated attackers to crash the server by sending deeply nested JSON. Attackers can send a request body with thousands of nested objects to exhaust the worker thread stack, terminating the process and dropping all connections.

Response Header Injection in CrowCpp Crow via Unvalidated Header Values

CrowCpp Crow through v1.3.1 HTTP is vulnerable to response header injection via unvalidated response header values.

HTTP applications (servers) based on Crow through 1.0+4 may reveal potentially sensitive uninitialized data from stack memory when fulfilling a request for a static file smaller than 16 KB.

HTTP applications (servers) based on Crow through 1.0+4 may allow a Use-After-Free and code execution when HTTP pipelining is used. The HTTP parser supports HTTP pipelining, but the asynchronous Connection layer is unaware of HTTP pipelining. Specifically, the Connection layer is unaware that it has begun processing a later request before it has finished processing an earlier request.

Crow before 1.0+4 has a heap-based buffer overflow via the function qs_parse in query_string.h. On successful exploitation this vulnerability allows attackers to remotely execute arbitrary code in the context of the vulnerable service.

Content Injection

This affects the package Crow before 0.3+4. When using attributes without quotes in the template, an attacker can manipulate the input to introduce additional attributes, potentially executing code. This may lead to a Cross-site Scripting (XSS) vulnerability, assuming an attacker can influence the value entered into the template. If the template is used to render user-generated content, this vulnerability may escalate to a persistent XSS vulnerability.

Path Traversal

This affects the package Crow before 0.3+4. It is possible to traverse directories to fetch arbitrary files from the server.