CVE-2026-46415— Caddy Defender trusted proxy client IP bypass

Caddy Defender trusted proxy client IP bypass

The Caddy Defender plugin is a middleware for Caddy that allows users to block or manipulate requests based on the client's IP address. Prior to version 0.10.1, Caddy Defender used `r.RemoteAddr` when evaluating whether a request should be blocked. `RemoteAddr` is the address of the immediate peer connected to Caddy. In deployments where Caddy is behind a trusted proxy, CDN, or load balancer, the immediate peer is usually the proxy, not the original client. Caddy resolves the original client address into its `client_ip` request variable after applying the configured `trusted_proxies` policy, but Defender did not use that value. As a result, clients from blocked IP ranges could bypass Defender when accessing Caddy through a trusted proxy whose own IP address was not blocked. This affects deployments that use Defender behind trusted proxies and expect it to enforce blocking based on the real client IP. The issue is fixed in version 0.10.1 by making Defender prefer Caddys resolved `client_ip` request variable when it is available. Defender falls back to `RemoteAddr` only when Caddy has not provided a resolved client IP. There is no complete workaround in affected Defender versions for deployments that rely on Caddy's trusted proxy client IP resolution. Until upgrading, affected users should enforce equivalent IP blocking at the trusted proxy, CDN, load balancer, firewall, or other edge layer before traffic reaches Caddy. Deployments where Caddy receives traffic directly from clients, without an intermediate trusted proxy, are not affected by this bypass.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N

访问控制不恰当

JasonLovesDoggo caddy-defender 权限许可和访问控制问题漏洞

JasonLovesDoggo caddy-defender是JasonLovesDoggo个人开发者开源的一款嵌入式服务器防御软件。 JasonLovesDoggo caddy-defender 0.10.1之前版本存在安全漏洞，该漏洞源于在评估请求是否需要阻止时使用了`r.RemoteAddr`而非解析后的真实客户端IP，可能导致来自已阻止IP范围的客户端通过受信任代理绕过防御。

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