Caddy is an extensible server platform that uses TLS by default. Prior to 2.11.4, forward_auth copy_headers deletes the exact client-supplied identity header before copying the trusted value from the auth gateway. But when the request later goes through php_fastcgi, Caddy normalizes HTTP headers into CGI variables by replacing - with _. This lets a client send an underscore alias that survives the forward_auth delete step but becomes the same PHP/FastCGI variable. Result: a remote client can inj
Caddy is an extensible server platform that uses TLS by default. Prior to 2.11.4, forward_auth copy_headers deletes the exact client-supplied identity header before copying the trusted value from the auth gateway. But when the request later goes through php_fastcgi, Caddy normalizes HTTP headers into CGI variables by replacing - with _. This lets a client send an underscore alias that survives the forward_auth delete step but becomes the same PHP/FastCGI variable. Result: a remote client can inject or sometimes override identity/group headers trusted by PHP/FastCGI applications behind Caddy. This vulnerability is fixed in 2.11.4.
为什么是这个 VPI(可解释·实验性)
VPI 计算依据
| 影响度 | 81.00 |
| 利用信号(存在 PoC) | ×1.20 |
| VPI | 97.20 |
VPI 公式 vpi-v1
| 来源 | CVSS 版本 | 基础评分 | 严重程度 | 向量字符串 | 评估日期 |
|---|---|---|---|---|---|
| NVDNIST | 3.1 | 8.1 | HIGH | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N | 2026. 06. 24. |
| OSV3rd | 3.1 | 8.1 | HIGH |
| CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N |
| 2026. 06. 17. |