A vulnerability in the CivetWeb library's function mghandleformrequest allows remote attackers to trigger a denial of service (DoS) condition. By sending a specially crafted HTTP POST request containing a null byte in the payload, the server enters an infinite loop during form data parsing. Multiple malicious requests will result in complete CPU exhaustion and render the service unresponsive to further requests.

This issue was fixed in commit 782e189. This issue affects only the library, standalone executable pre-built by vendor is not affected.

Vulnerability related to an unquoted search path in CivetWeb v1.16. This vulnerability allows a local attacker to execute arbitrary code with elevated privileges by placing a malicious executable in a directory that is scanned before the intended application path (C:\Program Files\CivetWeb\CivetWeb.exe --), due to the absence of quotes in the service configuration.

CivetWeb (commit 4a4f0c95) contains a heap and stack buffer overflow vulnerability in the readwebsocket() function that allows unauthenticated remote attackers to corrupt memory by sending compressed WebSocket frames when both USEZLIB and MGEXPERIMENTALINTERFACES are defined. Attackers can negotiate permessage-deflate during the WebSocket handshake and send a crafted frame with the RSV1 bit set, causing the server to write a 4-byte zlib sync trailer out-of-bounds past the allocated buffer, leading to heap metadata corruption, denial of service, or potential code execution.

Buffer Overflow in the URI parser of CivetWeb 1.14 through 1.16 (latest) allows a remote attacker to achieve remote code execution via a crafted HTTP request. This vulnerability is triggered during request processing and may allow an attacker to corrupt heap memory, potentially leading to denial of service or arbitrary code execution.