Readelf

readelf

Authoritative ELF structure inspection. When in doubt, trust the headers.

When to use readelf

Use readelf when you need to:

• verify ELF type, entry point, and architecture
• inspect sections, segments, dynamic libraries, or relocations
• confirm PIE, interpreter path, and symbol visibility details
• understand what the loader sees before patching or exploiting

Quick Start

# ELF header
readelf -h ./chall

# Program headers and interpreter
readelf -l ./chall

# Dynamic section
readelf -d ./chall

High-Value Workflows

Sections, symbols, and relocations

readelf -S ./chall
readelf -Ws ./chall
readelf -r ./chall

Notes, build IDs, and hardening clues

readelf -n ./chall
readelf -l ./chall

Shared-library dependencies

readelf -d ./chall | grep NEEDED
readelf -d ./chall | grep -E "RPATH|RUNPATH|SONAME"

Practical Notes

• Use readelf -l to confirm the PT_INTERP path before touching patchelf.
• readelf -d is the fastest way to answer libc and loader dependency questions.
• readelf -Ws helps explain why objdump or a debugger did or did not recover symbols.

Caveats

• readelf shows structure, not runtime values after relocation.
• It is ELF-only; use objdump or platform-native tooling for PE/Mach-O.
• For exploitability triage, combine with checksec and runtime observation.

Resources

No bundled scripts/, references/, or assets/. Use the GNU binutils documentation for less common flags like versioning, unwind info, and debug-section inspection.