CVE-2021-36080 — GNU LibreDWG 0.12.3.4163 through 0.12.3.4191 has a double-free in bit_chain_free (called from dwg_encode_MTEXT and dwg_encode_add_object)

Matched remediation archetype

Buffer bounds, memory safety, and memory corruption

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

• Identify affected native-code versions, build flags, architectures, parsers, codecs, drivers, and input paths in all shipped artifacts.
• Determine whether untrusted data reaches the affected routine and the process privilege, sandbox, and network exposure.
• Confirm statically linked, vendored, firmware, and platform-provided copies, not only package-manager records.

Remediate safely

• Apply the maintained upstream correction or replace the affected component, then rebuild every dependent artifact from clean inputs.
• Adopt bounds-checked interfaces, validated sizes and integer conversions, clear ownership, and memory-safe components where practical.
• Enable supported compiler and runtime hardening and add sanitized tests and fuzz regression seeds derived from non-weaponized fixtures.