The DCHECK Illusion: Chrome's "Trusted Path" Policy Creates Vulnerabilities

[Shrikant Bhosale <bhosaleone () gmail com>]

Subject: The DCHECK Illusion: Chrome's "Trusted Path" Policy Creates
Vulnerabilities

Full article:
https://potatobullet.com/chrome-dcheck-illusion-trusted-path-vulnerabilities/

Summary: An analysis of Chrome Mojo IPC finding 296 DCHECK instances across
mojo/core/ and mojo/public/cpp/bindings/lib/, at least 15 guarding
security-relevant conditions (bounds checks, offset validation, handle
state)
with ZERO protection in release builds. Error Principle classification:
Omission Debt with Dₑ = 0.95. Root cause is architectural — DCHECK as
security
boundary — not individual bugs.

Key numbers:
- 296 DCHECK instances in Mojo IPC
- 15+ guard security-critical conditions (compiled out in NDEBUG)
- CVE-2022-3075 ($100K+ bounty), CVE-2025-2783 same class, same root cause
- VRP-001 (2026) same class → dismissed "not a security bug"
- VRP-005 DataPipe DCHECK OOB → dismissed in 6 minutes
- No existing mitigation (MiraclePtr, CFG, ACG, ASLR, Site Isolation)
blocks this

Fix: Promote DCHECK to CHECK or if-return for all data crossing
renderer→browser IPC boundary.

— Shrikant Bhosale (The Debt Collector)
_______________________________________________
Sent through the Full Disclosure mailing list
https://nmap.org/mailman/listinfo/fulldisclosure
Web Archives & RSS: https://seclists.org/fulldisclosure/