When script_alias maps a URL prefix to a directory outside DocumentRoot, mod_auth evaluates directory-based access controls against the DocumentRoot-relative path while mod_cgi executes the script at the ScriptAlias-resolved path. This path mismatch allows unauthenticated access to CGI scripts that directory rules were meant to protect.
This vulnerability is associated with program files lib/inets/src/http_server/mod_alias.erl, lib/inets/src/http_server/mod_auth.erl, and lib/inets/src/http_server/mod_cgi.erl.
This issue affects OTP from OTP 17.0 until OTP 28.4.2, 27.3.4.10 and 26.2.5.19 corresponding to inets from 5.10 until 9.6.2, 9.3.2.4 and 9.1.0.6.
No advisories yet.
Solution
No solution given by the vendor.
Workaround
* Move CGI scripts inside DocumentRoot and use alias instead of script_alias to ensure mod_auth resolves the correct path. * Apply URL-based access controls at a reverse proxy layer to block unauthenticated access to the script_alias URL prefix. * Remove mod_cgi from the httpd modules chain if CGI functionality is not required.
Tue, 07 Apr 2026 15:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | Incorrect Authorization vulnerability in Erlang OTP (inets modules) allows unauthenticated access to CGI scripts protected by directory rules when served via script_alias. When script_alias maps a URL prefix to a directory outside DocumentRoot, mod_auth evaluates directory-based access controls against the DocumentRoot-relative path while mod_cgi executes the script at the ScriptAlias-resolved path. This path mismatch allows unauthenticated access to CGI scripts that directory rules were meant to protect. This vulnerability is associated with program files lib/inets/src/http_server/mod_alias.erl, lib/inets/src/http_server/mod_auth.erl, and lib/inets/src/http_server/mod_cgi.erl. This issue affects OTP from OTP 17.0 until OTP 28.4.2, 27.3.4.10 and 26.2.5.19 corresponding to inets from 5.10 until 9.6.2, 9.3.2.4 and 9.1.0.6. | |
| Title | ScriptAlias CGI targets bypass directory auth in inets httpd (mod_auth vs mod_cgi path mismatch) | |
| First Time appeared |
Erlang
Erlang erlang\/otp |
|
| Weaknesses | CWE-863 | |
| CPEs | cpe:2.3:a:erlang:erlang\/otp:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Erlang
Erlang erlang\/otp |
|
| References |
|
|
| Metrics |
cvssV4_0
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Projects
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Status: PUBLISHED
Assigner: EEF
Published:
Updated: 2026-04-07T14:38:09.190Z
Reserved: 2026-03-03T14:40:00.590Z
Link: CVE-2026-28808
Updated: 2026-04-07T13:14:12.725Z
Status : Awaiting Analysis
Published: 2026-04-07T13:16:46.320
Modified: 2026-04-07T13:20:11.643
Link: CVE-2026-28808
No data.
OpenCVE Enrichment
No data.