This bug emerges when IAST (Interactive Application Security Testing) hooks into Linux terminal processes at runtime. Under certain conditions—often during high-frequency stdin/stdout interactions—it triggers race conditions in pseudo-terminal layer handling. The result: broken pipes, stalled output, and commands that hang until killed. In systems with layered security monitors, the disruption spreads fast across developer workflows and CI pipelines.
Root cause analysis points to conflicts between IAST instrumentation and the PTY (pseudo-terminal) subsystem in Linux. IAST modifies program execution to track security events. When those hooks intercept terminal I/O too aggressively, the PTY buffer can desynchronize, leading to corrupted streams. This manifests as partial output, missing prompts, or total session lockup.
Mitigation requires precision. Updating to the latest IAST agent builds fixes known trigger conditions. For environments where patching is slow, isolating IAST runtime from interactive shells is safer—configure agents to monitor only non-interactive processes. Some teams deploy containerized shells or use detached terminal multiplexers like screen or tmux to reduce PTY conflicts.