Trenchant (L3Harris)

iOS User Space Sandbox Escape - Vulnerability Researcher

Trenchant (L3Harris)

GlobalFullTimePosted Jul 31, 2026

Job description

We are looking for a deeply experienced iOS userspace researcher who has already delivered sandbox escapes, privileged-daemon vulnerabilities or equivalent exploit components. The work is focused on real trust boundaries exposed through Mach, XPC, private frameworks, privileged services and entitlement-gated functionality.

This is not an application-security or jailbreak-usage role. What you’ll work on

  • Privileged iOS daemons, frameworks and services reachable from sandboxed application or browser contexts.
  • Mach, XPC, NSXPC, serialisation and object-bridging boundaries.
  • Memory corruption, logic vulnerabilities, confused-deputy conditions, race conditions and entitlement bypasses.
  • Sandbox profiles, service registration, entitlement checks and cross-process trust relationships.
  • Private-framework and daemon-protocol reverse engineering across iOS releases and arm64e devices.
  • Exploit-chain integration with browser and kernel researchers when required. What you’ll deliver
  • Original iOS userspace vulnerabilities that cross sandbox, entitlement, process or service boundaries.
  • Reliable sandbox-escape exploit components suitable for integration into broader chains.
  • Prioritised attack-surface maps for privileged services, framework brokers and entitlement-gated functionality.
  • Triggers, PoCs, exploitation strategy, affected-version notes, assumptions and clear technical handover.
  • Reusable tooling for service discovery, message generation, daemon instrumentation, entitlement analysis and variant research. What we’re looking for
  • Proven delivery of iOS sandbox escapes, privileged-daemon vulnerabilities or comparable userspace exploit components.
  • Deep knowledge of iOS process isolation, code signing, entitlements, sandbox profiles and launch/service models.
  • Strong reverse engineering across Objective-C, Swift and C/C++, including private frameworks and stripped binaries.
  • Practical expertise with Mach messaging, XPC/NSXPC, serialisation formats and asynchronous service interactions.
  • Advanced ARM64/arm64e userspace exploitation, including modern heap behaviour, PAC-aware strategies and constrained code execution.
  • The ability to reason about chainability, target variation and reliability rather than stopping at a one-time daemon crash.
  • A consistent history of independently finishing complex research. Strong signals
  • Public iOS security credits, jailbreak-chain research or comparable exploit-chain delivery.
  • Experience chaining browser compromise into an iOS userspace sandbox escape.
  • Custom XPC/Mach fuzzing, service-introspection or firmware-analysis tooling.
  • Research across multiple major iOS generations and arm64e hardware families.
  • Strong patch-diffing and variant-hunting results. How we work
  • Fully remote, with high autonomy and direct collaboration with browser and kernel specialists.
  • We value technically meaningful delivery, clean handover and reproducibility over activity metrics or polished theatre.
  • Public CVEs are useful but not required.