feat(crawler): guard Chromium chapter navigation against internal targets

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/Cargo.lock

@@ -1558,7 +1558,7 @@ checksum = "c41e0c4fef86961ac6d6f8a82609f55f31b05e4fce149ac5710e439df7619ba4"
 
 [[package]]
 name = "mangalord"
-version = "0.91.0"
+version = "0.92.0"
 dependencies = [
  "anyhow",
  "argon2",

backend/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "mangalord"
-version = "0.91.0"
+version = "0.92.0"
 edition = "2021"
 default-run = "mangalord"
 

backend/src/crawler/content.rs

@@ -18,7 +18,7 @@ use uuid::Uuid;
 
 use crate::crawler::detect::PageError;
 use crate::crawler::rate_limit::HostRateLimiters;
-use crate::crawler::safety::{fetch_stream, looks_like_image, DownloadAllowlist};
+use crate::crawler::safety::{ensure_public_target, fetch_stream, looks_like_image, DownloadAllowlist};
 use crate::crawler::session::{self, ChapterProbe};
 use crate::storage::{Storage, StorageError};
 
@@ -95,6 +95,19 @@ enum ChapterFetchOutcome {
     PersistentTransient,
 }
 
+/// Refuse to navigate Chromium at a chapter URL that points inside the
+/// deployment. The image-download path goes through `is_safe_url`, but
+/// `new_page` is a second network surface: a `chapter_sources` row whose
+/// host resolves to (or was crafted to be) a private IP would otherwise let
+/// the headless browser probe `postgres:5432`, the cloud metadata service,
+/// etc. Reuses the allowlist-free `ensure_public_target` (scheme +
+/// private-IP literal check) since there is no per-host allowlist for the
+/// scraped catalog itself.
+fn guard_nav_url(source_url: &str) -> anyhow::Result<()> {
+    ensure_public_target(source_url)
+        .map_err(|e| anyhow::anyhow!("refuse to navigate unsafe chapter URL {source_url}: {e}"))
+}
+
 /// Single rate-limited Chromium navigation to the chapter URL,
 /// returning the page HTML. Extracted from `sync_chapter_content` so
 /// the recircuit loop can call it once per attempt.
@@ -103,6 +116,7 @@ async fn fetch_chapter_html_once(
     rate: &HostRateLimiters,
     source_url: &str,
 ) -> anyhow::Result<String> {
+    guard_nav_url(source_url)?;
     rate.wait_for(source_url).await?;
     let page = browser
         .new_page(source_url)
@@ -609,6 +623,27 @@ mod tests {
     use super::*;
     use crate::storage::LocalStorage;
 
+    #[test]
+    fn guard_nav_url_rejects_private_and_loopback_targets() {
+        // A chapter_sources row that resolves to / was crafted as an
+        // internal target must be refused before Chromium navigates.
+        for url in [
+            "http://127.0.0.1:5432/",
+            "http://169.254.169.254/latest/meta-data/",
+            "http://10.0.0.1/chapter/1",
+            "http://localhost:8080/",
+            "file:///etc/passwd",
+        ] {
+            assert!(guard_nav_url(url).is_err(), "must reject {url}");
+        }
+    }
+
+    #[test]
+    fn guard_nav_url_allows_public_chapter_urls() {
+        assert!(guard_nav_url("https://reader.example.com/chapter/42").is_ok());
+        assert!(guard_nav_url("http://manga-host.test/c/1/p/2").is_ok());
+    }
+
     #[tokio::test]
     async fn cleanup_orphans_deletes_written_keys() {
         let dir = tempfile::tempdir().unwrap();

frontend/package.json

@@ -1,6 +1,6 @@
 {
   "name": "mangalord-frontend",
-  "version": "0.91.0",
+  "version": "0.92.0",
   "private": true,
   "type": "module",
   "scripts": {