Erlang OTP mod_auth mod_auth.secret_path access control

Summaryinfo

A vulnerability was found in Erlang OTP and classified as problematic. This affects the function mod_auth.secret_path of the component mod_auth. Executing a manipulation can lead to access control. This vulnerability is tracked as CVE-2026-73270. The attack can be launched remotely. No exploit exists.

Detailsinfo

A vulnerability classified as problematic was found in Erlang OTP (the affected version is unknown). This vulnerability affects the function mod_auth.secret_path of the component mod_auth. The manipulation with an unknown input leads to a access control vulnerability. The CWE definition for the vulnerability is CWE-284. The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor. As an impact it is known to affect confidentiality. CVE summarizes:

Improper Handling of Case Sensitivity vulnerability in Erlang/OTP inets httpd allows a remote unauthenticated attacker to read files inside a mod_auth protected directory by requesting them with different casing, on deployments whose filesystem is case-insensitive. mod_auth:secret_path/3 decides whether a resolved filesystem path lies inside a protected directory block by running the configured directory path through re:run/3 without the caseless option. A request for /secret/file against a directory configured as /Secret therefore does not match, so the request is treated as unprotected and no authentication challenge is issued, while the filesystem resolves the differently cased path to the same file and mod_get serves it. Deployments on case-sensitive filesystems are unaffected, because there the filesystem itself rejects the mismatched casing. This issue affects OTP from OTP 17.0 before OTP 27.3.4.17, from OTP 28.0 before OTP 28.5.0.6, and from OTP 29.0 before OTP 29.0.6, corresponding to inets from 5.10 before 9.3.2.7, from 9.4 before 9.6.2.3, and from 9.7 before 9.7.2. Whether OTP before OTP 17.0, corresponding to inets before 5.10, is affected is unknown.

The advisory is available at github.com. This vulnerability was named CVE-2026-73270 since 08/17/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 09/01/2026). This vulnerability is assigned to T1068 by the MITRE ATT&CK project.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

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Productinfo

Vendor

• Erlang

Name

• OTP

Website

• Product: https://github.com/erlang/otp/

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