dsh-web-fetch-enhanced

The native web_fetch in DeepSeek Harness enforces a hard SSRF boundary by rejecting all non-public addresses. That guard is correct for public traffic, yet it blinds the Agent in transparent-proxy and private-network setups: Clash and Mihomo Fake-IP mode resolve domains into 198.18.0.0/15, and intranet doc sites or self-hosted knowledge bases are blocked before any proxy can take over. This plugin lets administrators declare two layers of explicit exceptions in the DSH Web settings page—a CIDR whitelist for which non-public IPv4/IPv6 ranges may be permitted, and an optional hostname whitelist to narrow access to exact sites. With nothing configured, behaviour is identical to the native provider.

Under the hood the security model is thorough: DNS full-answer validation with connection pinning ensures every resolved address is compliant, same-origin-only redirects are re-validated at each hop, requests are restricted to anonymous GETs with no cookies or authorization headers, response bytes and decoded characters are hard-capped, IPv4-mapped IPv6 and active DNS64 targets are covered, and non-public IP literals are strictly barred from riding the global outbound proxy—eliminating intranet SSRF risk. Rules take effect immediately after saving, with no Host restart required.

Well suited for teams and individual admins who run transparent proxies (Clash/Mihomo Fake-IP), need the Agent to read internal documentation or private APIs, and want zero changes on the model side while preserving a strict default-deny posture.