In OpenResty through 1.13.6.1, URI parameters are obtained using the ngx.req.get_uri_args and ngx.req.get_post_args functions that ignore parameters beyond the hundredth one, which might allow remote attackers to bypass intended access restrictions or interfere with certain Web Application Firewall (ngx_lua_waf or X-WAF) products. NOTE: the vendor has reported that 100 parameters is an intentional default setting, but is adjustable within the API. The vendor's position is that a security-relevant misuse of the API by a WAF product is a vulnerability in the WAF product, not a vulnerability in OpenResty

An issue was discovered in OpenResty before 1.15.8.4. ngx_http_lua_subrequest.c allows HTTP request smuggling, as demonstrated by the ngx.location.capture API.

ngx_http_lua_module (aka lua-nginx-module) before 0.10.16 in OpenResty allows unsafe characters in an argument when using the API to mutate a URI, or a request or response header.

A security issue in nginx resolver was identified, which might allow an attacker who is able to forge UDP packets from the DNS server to cause 1-byte memory overwrite, resulting in worker process crash or potential other impact.

The HTTP/2 protocol allows a denial of service (server resource consumption) because request cancellation can reset many streams quickly, as exploited in the wild in August through October 2023.

An issue in OpenResty lua-nginx-module v.0.10.26 and before allows a remote attacker to conduct HTTP request smuggling via a crafted HEAD request.

In lj_str_hash.c in OpenResty 1.19.3.1 through 1.25.3.1, the string hashing function (used during string interning) allows HashDoS (Hash Denial of Service) attacks. An attacker could cause excessive resource usage during proxy operations via crafted requests, potentially leading to a denial of service with relatively few incoming requests. This vulnerability only exists in the OpenResty fork in the openresty/luajit2 GitHub repository. The LuaJIT/LuaJIT repository. is unaffected.