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How the CVE Works:
CVE-2025-26307 is a memory leak vulnerability in libming v0.4.8, specifically in the `parseSWF_IMPORTASSETS2` function within util/parser.c. When parsing a maliciously crafted SWF file, the function fails to release allocated memory properly, leading to gradual resource exhaustion. Attackers can exploit this flaw by repeatedly submitting crafted SWF files, causing the application to consume excessive memory over time, resulting in a denial-of-service (DoS) condition. The issue stems from improper handling of asset imports during SWF parsing, where dynamically allocated memory is not freed after processing.
DailyCVE Form:
Platform: libming
Version: 0.4.8
Vulnerability: Memory leak
Severity: Medium
Date: 2025-04-17
What Undercode Say:
Exploitation:
1. Craft a malicious SWF file triggering `parseSWF_IMPORTASSETS2`.
- Use a script to repeatedly submit the file to the target:
while true; do curl -F "[email protected]" http://target/upload; done
- Monitor memory usage (
toporhtop) to confirm exploitation.
Mitigation:
1. Patch libming to the latest version.
2. Implement input validation for SWF files:
def validate_swf(file): if not file.startswith(b"FWS") and not file.startswith(b"CWS"): raise InvalidSWFError
3. Use memory limits via `cgroups` or containerization:
docker run --memory="500m" app_with_libming
Detection:
1. Check for memory leaks using `valgrind`:
valgrind --leak-check=full ./parsing_tool exploit.swf
2. Audit logs for repeated SWF uploads:
grep "SWF upload" /var/log/app.log | awk '{print $1}' | uniq -c | sort -nr
Code Fix Example:
Patch `util/parser.c` to free allocated memory:
void parseSWF_IMPORTASSETS2(SWF swf) {
AssetData assets = parseAssets(swf);
if (assets) {
processAssets(assets);
free(assets); // Fix: Release memory
}
}
Analytics:
- Attack Vector: Local/Remote (file upload)
- Complexity: Low (no code execution)
- Impact: DoS via memory exhaustion
- CVSS 4.0: `CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:H` (5.5 Medium)
Sources:
Reported By: nvd.nist.gov
Extra Source Hub:
Undercode
