CVE-2025-8843
📋 TL;DR
A heap-based buffer overflow vulnerability in NASM Netwide Assembler 2.17rc0 allows attackers with local access to potentially execute arbitrary code or cause denial of service. This affects users who compile or process assembly code with vulnerable NASM versions. The vulnerability is in the macho_no_dead_strip function in outmacho.c.
💻 Affected Systems
- NASM Netwide Assembler
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Local privilege escalation leading to full system compromise via arbitrary code execution.
Likely Case
Denial of service through application crash when processing malicious assembly files.
If Mitigated
Limited impact if proper sandboxing and privilege separation are implemented.
🎯 Exploit Status
Exploit details have been publicly disclosed but require local access and specific assembly file processing.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2.17rc1 or later
Vendor Advisory: https://bugzilla.nasm.us/show_bug.cgi?id=3392934
Restart Required: No
Instructions:
1. Visit https://www.nasm.us/pub/nasm/releasebuilds/ 2. Download latest version 3. Compile and install following official documentation 4. Replace existing nasm binary
🔧 Temporary Workarounds
Avoid Mach-O compilation
allDo not use NASM to compile Mach-O format assembly files until patched.
🧯 If You Can't Patch
- Restrict local access to NASM installation to trusted users only.
- Monitor for abnormal process crashes or memory usage patterns in NASM processes.
🔍 How to Verify
Check if Vulnerable:
Run 'nasm -v' and check if output shows version 2.17rc0.Check Version:
nasm -vVerify Fix Applied:
Run 'nasm -v' and confirm version is 2.17rc1 or later.📡 Detection & Monitoring
Log Indicators:
- Segmentation fault or abnormal termination of nasm processes
- High memory usage by nasm processes
Network Indicators:
- Not applicable - local exploitation only
SIEM Query:
Process:name='nasm' AND (EventID=1000 OR MemoryUsage>threshold)🔗 References
- https://bugzilla.nasm.us/show_bug.cgi?id=3392934
- https://drive.google.com/file/d/1JRHWdjW6FGHDV0CMJe8VinmCQ4vP9ZpR/view?usp=drive_link
- https://vuldb.com/?ctiid.319377
- https://vuldb.com/?id.319377
- https://vuldb.com/?submit.623185
- https://vuldb.com/?submit.623186
- https://bugzilla.nasm.us/show_bug.cgi?id=3392934
- https://vuldb.com/?submit.623186
