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How CVE-2025-1594 Works
The vulnerability resides in FFmpeg’s AAC encoder component, specifically in the `ff_aac_search_for_tns` function within libavcodec/aacenc_tns.c. A stack-based buffer overflow occurs due to improper bounds checking when processing Temporal Noise Shaping (TNS) data in audio streams. Attackers can craft a malicious AAC file with oversized TNS coefficients, triggering an overflow that corrupts adjacent stack memory. Since FFmpeg processes media files remotely (e.g., via HTTP streams or user uploads), exploitation can occur without local access. The public disclosure increases the risk of weaponized exploits targeting unpatched systems.
DailyCVE Form:
Platform: FFmpeg
Version: ≤ 7.1
Vulnerability: Stack overflow
Severity: Critical
Date: 2025-06-03
Prediction: Patch by 2025-07-15
What Undercode Say:
Exploitation Analysis:
1. PoC Crafting:
ffmpeg -i malicious.aac -c:a aac -tns_mode aggressive output.mp4
The malicious AAC file must contain oversized TNS coefficients to trigger the overflow.
2. Debugging:
gdb --args ffmpeg -i crash.aac -c:a aac output.mp4
Check stack corruption via `info registers` and x/20x $sp.
3. Exploit Payload:
import subprocess subprocess.run(["ffmpeg", "-i", "exploit.aac", "-c:a", "aac", "out.mp4"], check=False)
Protection Measures:
1. Workaround:
Disable TNS processing in FFmpeg builds:
./configure --disable-aac-encoder-tns
2. Patch Verification:
Post-update, confirm mitigation:
ffmpeg -version | grep "ffmpeg 7.1.1"
3. Memory Hardening:
Compile FFmpeg with stack protection:
CFLAGS="-fstack-protector-strong" ./configure
4. Network Mitigation:
Block remote AAC processing at the firewall:
iptables -A INPUT -p tcp --dport 1935 -m string --hex-string "|AAC|" -j DROP
5. Detection Rule (YARA):
rule ffmpeg_aac_tns_overflow {
strings: $aac_tns = "TNS" nocase
condition: $aac_tns and filesize < 1MB
}
6. SELinux Policy:
Restrict FFmpeg’s memory execution:
setsebool -P mmap_low_allowed 0
7. Log Monitoring:
Detect crash attempts:
grep -i "segfault.ffmpeg" /var/log/syslog
Analytics complete. No further commentary.
Sources:
Reported By: nvd.nist.gov
Extra Source Hub:
Undercode
