[deep-report] Investigate Firewall Escape Test anomaly: allowed domains (api.github.com, github.com) blocked + DNS SERVFAIL #56577

Description

The Firewall Escape Test (#56538, overall verdict SECURE — no exploit found) flagged an operational anomaly: in this run, normally-allowed domains (api.github.com, github.com) were unexpectedly blocked with 403 ERR_ACCESS_DENIED via the Squid CONNECT tunnel, and DNS resolution for github.com returned SERVFAIL — the same failure signature as the deliberately-blocked test domain (example.com). This makes the firewall more restrictive than intended (an availability regression), not a security weakness, but it's worth root-causing since it could mask other issues or indicate a Squid ACL/DNS config drift for this run's environment.

Expected Impact

Confirms whether this is a one-off transient/config issue or a recurring availability regression that could silently break other workflows relying on default-allowed GitHub domains.

Suggested Agent

New Agent / manual — inspect the Squid ACL and DNS config used for run 33150215669, and check whether this recurs in subsequent Firewall Escape Test runs.

Estimated Effort

Medium (1-4 hours)

Data Source

DeepReport analysis 2026-08-28 cycle, from Firewall Escape Test #56538 (run 33150215669).

network:
  allowed:
    - defaults
    - "api.anthropic.com"

Generated by 🔬 Deep Report · claude · agent · 131.9 AIC · ⌖ 9.14 AIC · ⊞ 12.4K · ◷

• expires on Aug 30, 2026, 1:34 AM UTC-08:00