CVE-2023-4156

What it actually does

Heap out-of-bounds read in builtin.c allowing memory contents beyond allocated buffers to be read, resulting in process crashes or disclosure of sensitive information.

Why it matters to the business

Unexpected application crashes and potential exposure of confidential data can disrupt operations and compromise data confidentiality in environments relying on the affected text-processing package.

How an attack unfolds

An attacker crafts malicious input or scripts that invoke builtin functions in gawk, triggering the out-of-bounds read to either destabilize the process or leak memory-resident data.

How to fix it

Upgrade to the fixed commit 8f42e9b75a55401fa9dfdf14d49fbe5396c6ce92 or later equivalent patched release of the gawk package; rebuild from source if necessary and verify the fix is present.

How to confirm the fix worked

Confirm gawk version and source commit; run regression tests with known out-of-bounds triggering inputs and monitor for absence of crashes or memory errors.

Typical attack path

1. Locate systems running the vulnerable gawk package
2. Prepare input designed to exercise builtin.c functions with oversized or malformed data
3. Invoke gawk on the crafted input via command line or script
4. Capture resulting crash dumps or observe leaked memory artifacts

How to detect it

Search system and application logs for gawk segmentation faults or abnormal terminations; examine core dumps or memory artifacts for signs of unexpected buffer access around builtin functions.

What your security team should do

• Prioritize patching gawk across all systems due to available exploit code
• Restrict execution of gawk on untrusted inputs until updated
• Audit scripts and automation that invoke gawk for input sanitization