Reject suspicious encoded characters

Co-authored-by: Kevin Pollet <pollet.kevin@gmail.com>

docs/content/routing/entrypoints.md

@@ -127,6 +127,14 @@ They can be defined by using a file (YAML or TOML) or CLI arguments.
           trustedIPs:
             - "127.0.0.1"
             - "192.168.0.1"
+        encodedCharacters:
+          allowEncodedSlash: true
+          allowEncodedBackSlash: true
+          allowEncodedNullCharacter: true
+          allowEncodedSemicolon: true
+          allowEncodedPercent: true
+          allowEncodedQuestionMark: true
+          allowEncodedHash: true
     ```
 
     ```toml tab="File (TOML)"
@@ -152,6 +160,14 @@ They can be defined by using a file (YAML or TOML) or CLI arguments.
         [entryPoints.name.forwardedHeaders]
           insecure = true
           trustedIPs = ["127.0.0.1", "192.168.0.1"]
+        [entryPoints.name.encodedCharacters]
+          allowEncodedSlash = true
+          allowEncodedBackSlash = true
+          allowEncodedNullCharacter = true
+          allowEncodedSemicolon = true
+          allowEncodedPercent = true
+          allowEncodedQuestionMark = true
+          allowEncodedHash = true
     ```
 
     ```bash tab="CLI"
@@ -168,6 +184,13 @@ They can be defined by using a file (YAML or TOML) or CLI arguments.
     --entryPoints.name.proxyProtocol.trustedIPs=127.0.0.1,192.168.0.1
     --entryPoints.name.forwardedHeaders.insecure=true
     --entryPoints.name.forwardedHeaders.trustedIPs=127.0.0.1,192.168.0.1
+    --entryPoints.name.encodedCharacters.allowEncodedSlash=true
+    --entryPoints.name.encodedCharacters.allowEncodedBackSlash=true
+    --entryPoints.name.encodedCharacters.allowEncodedNullCharacter=true
+    --entryPoints.name.encodedCharacters.allowEncodedSemicolon=true
+    --entryPoints.name.encodedCharacters.allowEncodedPercent=true
+    --entryPoints.name.encodedCharacters.allowEncodedQuestionMark=true
+    --entryPoints.name.encodedCharacters.allowEncodedHash=true
     ```
 
 ### Address
@@ -455,6 +478,232 @@ You can configure Traefik to trust the forwarded headers information (`X-Forward
     --entryPoints.web.forwardedHeaders.connection=foobar
     ```
 
+### Encoded Characters
+
+You can configure Traefik to control the handling of encoded characters in request paths for security purposes.
+By default, Traefik rejects requests containing certain encoded characters that could be used in path traversal or other security attacks.
+
+!!! warning "Security Considerations"
+
+    Allowing certain encoded characters may expose your application to security vulnerabilities.
+
+??? info "`encodedCharacters.allowEncodedSlash`"
+
+    _Optional, Default=false_
+
+    Controls whether requests with encoded slash characters (`%2F` or `%2f`) in the path are allowed.
+
+    ```yaml tab="File (YAML)"
+    ## Static configuration
+    entryPoints:
+      web:
+        address: ":80"
+        encodedCharacters:
+          allowEncodedSlash: true
+    ```
+
+    ```toml tab="File (TOML)"
+    ## Static configuration
+    [entryPoints]
+      [entryPoints.web]
+        address = ":80"
+
+        [entryPoints.web.encodedCharacters]
+          allowEncodedSlash = true
+    ```
+
+    ```bash tab="CLI"
+    ## Static configuration
+    --entryPoints.web.address=:80
+    --entryPoints.web.encodedCharacters.allowEncodedSlash=true
+    ```
+
+??? info "`encodedCharacters.allowEncodedBackSlash`"
+
+    _Optional, Default=false_
+
+    Controls whether requests with encoded back slash characters (`%5C` or `%5c`) in the path are allowed.
+
+    ```yaml tab="File (YAML)"
+    ## Static configuration
+    entryPoints:
+      web:
+        address: ":80"
+        encodedCharacters:
+          allowEncodedBackSlash: true
+    ```
+
+    ```toml tab="File (TOML)"
+    ## Static configuration
+    [entryPoints]
+      [entryPoints.web]
+        address = ":80"
+
+        [entryPoints.web.encodedCharacters]
+          allowEncodedBackSlash = true
+    ```
+
+    ```bash tab="CLI"
+    ## Static configuration
+    --entryPoints.web.address=:80
+    --entryPoints.web.encodedCharacters.allowEncodedBackSlash=true
+    ```
+
+??? info "`encodedCharacters.allowEncodedNullCharacter`"
+
+    _Optional, Default=false_
+
+    Controls whether requests with encoded null characters (`%00`) in the path are allowed.
+
+    ```yaml tab="File (YAML)"
+    ## Static configuration
+    entryPoints:
+      web:
+        address: ":80"
+        encodedCharacters:
+          allowEncodedNullCharacter: true
+    ```
+
+    ```toml tab="File (TOML)"
+    ## Static configuration
+    [entryPoints]
+      [entryPoints.web]
+        address = ":80"
+
+        [entryPoints.web.encodedCharacters]
+          allowEncodedNullCharacter = true
+    ```
+
+    ```bash tab="CLI"
+    ## Static configuration
+    --entryPoints.web.address=:80
+    --entryPoints.web.encodedCharacters.allowEncodedNullCharacter=true
+    ```
+
+??? info "`encodedCharacters.allowEncodedSemicolon`"
+
+    _Optional, Default=false_
+
+    Controls whether requests with encoded semicolon characters (`%3B` or `%3b`) in the path are allowed.
+
+    ```yaml tab="File (YAML)"
+    ## Static configuration
+    entryPoints:
+      web:
+        address: ":80"
+        encodedCharacters:
+          allowEncodedSemicolon: true
+    ```
+
+    ```toml tab="File (TOML)"
+    ## Static configuration
+    [entryPoints]
+      [entryPoints.web]
+        address = ":80"
+
+        [entryPoints.web.encodedCharacters]
+          allowEncodedSemicolon = true
+    ```
+
+    ```bash tab="CLI"
+    ## Static configuration
+    --entryPoints.web.address=:80
+    --entryPoints.web.encodedCharacters.allowEncodedSemicolon=true
+    ```
+
+??? info "`encodedCharacters.allowEncodedPercent`"
+
+    _Optional, Default=false_
+
+    Controls whether requests with encoded percent characters (`%25`) in the path are allowed.
+
+    ```yaml tab="File (YAML)"
+    ## Static configuration
+    entryPoints:
+      web:
+        address: ":80"
+        encodedCharacters:
+          allowEncodedPercent: true
+    ```
+
+    ```toml tab="File (TOML)"
+    ## Static configuration
+    [entryPoints]
+      [entryPoints.web]
+        address = ":80"
+
+        [entryPoints.web.encodedCharacters]
+          allowEncodedPercent = true
+    ```
+
+    ```bash tab="CLI"
+    ## Static configuration
+    --entryPoints.web.address=:80
+    --entryPoints.web.encodedCharacters.allowEncodedPercent=true
+    ```
+
+??? info "`encodedCharacters.allowEncodedQuestionMark`"
+
+    _Optional, Default=false_
+
+    Controls whether requests with encoded question mark characters (`%3F` or `%3f`) in the path are allowed.
+
+    ```yaml tab="File (YAML)"
+    ## Static configuration
+    entryPoints:
+      web:
+        address: ":80"
+        encodedCharacters:
+          allowEncodedQuestionMark: true
+    ```
+
+    ```toml tab="File (TOML)"
+    ## Static configuration
+    [entryPoints]
+      [entryPoints.web]
+        address = ":80"
+
+        [entryPoints.web.encodedCharacters]
+          allowEncodedQuestionMark = true
+    ```
+
+    ```bash tab="CLI"
+    ## Static configuration
+    --entryPoints.web.address=:80
+    --entryPoints.web.encodedCharacters.allowEncodedQuestionMark=true
+    ```
+
+??? info "`encodedCharacters.allowEncodedHash`"
+
+    _Optional, Default=false_
+
+    Controls whether requests with encoded hash characters (`%23`) in the path are allowed.
+
+    ```yaml tab="File (YAML)"
+    ## Static configuration
+    entryPoints:
+      web:
+        address: ":80"
+        encodedCharacters:
+          allowEncodedHash: true
+    ```
+
+    ```toml tab="File (TOML)"
+    ## Static configuration
+    [entryPoints]
+      [entryPoints.web]
+        address = ":80"
+
+        [entryPoints.web.encodedCharacters]
+          allowEncodedHash = true
+    ```
+
+    ```bash tab="CLI"
+    ## Static configuration
+    --entryPoints.web.address=:80
+    --entryPoints.web.encodedCharacters.allowEncodedHash=true
+    ```
+
 ### Transport
 
 #### `respondingTimeouts`